How about a kalk discussion
- Thread starter jfl14609
- Start date
Right now my topoff is strictly limewater and 2-part when my Ca and Alk fall out of spec. I have my ACJr turn on a maxijet (with a valve for control) 3x per night and run for 1 minute each time. Which is currently giving me the correct amount of water for my winter time evap.
I'm going to be running a float switch hooked to my ACJr (with some help from StashuDave) to control the pump, as soon as the parts come in. This way I'll be dosing smaller amounts all day long.
I'm going to be running a float switch hooked to my ACJr (with some help from StashuDave) to control the pump, as soon as the parts come in. This way I'll be dosing smaller amounts all day long.
Let's start with a comparison of methods.
There are 4 mainstream ways to meet the system's needs for alkalinity and calcium. They are: waterchanges with high calcium alkalinity salt mixes; dosing a balanced calcium carbonate/bicarbonate mix via calcium reactor; 2 part dosing(aka balling method) with calcium chloride for calcium and baking soda or a commercial alkalinity mix for alkalinity;and last but not least limewater ( calcium hydroxide) dosing for a balanced mix of alkalinity and calcium.
Other than salt mix none add substantial magnesium. Commercial 2 part calcium additions may contain some but not likely enough to meet a system's needs for magnesium. So for now we'llset magnesium aside.
Water changes with a salt mix that is high in calcium and or alkalinity. This will work for some tanks but may cause undesireable rapid changes in the alkainity at the point of the water change which can be harmful to some corals. So somewhat frequent smaller , 25% changes are useful, in my opinion.
Calcium reactors dissolve aragonite (calcium carbonate) by passing acidified water high in carbonic acid(H2CO3) through media which is largely coral skeleton. CO2 which is injected into them quickly turns to carbonic acid dropping the ph to levels suitable to dissolve the media . Tuning them in can be tedious and most who use them experience chronically low ph since the effluent ph on calcium reactors is around 6.7 give or take 0.2. I used one for several years along with limewater dosing and was able to balance ph nicely but alkalinity was higher(12dkh+) than I liked when my system developed into a low nutrient system, so I kept the limewater and took the calcium reactor off line . Limewater alone with occasional boosting with baking soda works well for me. More about that later.
Two part dosing(aka the balling method).
Easy via pour in or dosing pumps.
Calcium chloride is used for the calcium. The chloride disassociates and adds to the chloride in the system. Not a big concern since chloride in sea water is about 19,000ppm, so the extra chloride form dosing is not likely to upset natural ratios of elements very much. Nonetheless, over a long period of time excess chlorides can build up particularly if regular water changes are not done or expensive special balling system salt mixes short on chloride are not used.
Commercial alkalinity supplements are primarily carbonate or bicarbonate plus some impurities/trace elements. 90% of alkalinity is seawater is bicarbonate or carbonate. Corals use bicarbonate. The rest is boron, and a slew of other things form some forms of phosphate to silicate. Baking soda unbaked is bicarbonate(HCO3) when baked it is carbonate (CO3). The proportion of carbonate to bicarbonate in nsw is about 1 to 5.
When I use two part dosing to supplement, I use baking soda and calcium chloride from brs. The commercial mixes are convenient for small systems though.
I've tried them all and limewater dosing from a still reservoir along with a high calcium / magnesium salt( Coralife in my case: magnesium 1400ppm, calcium 520ppm and alkalinity at 8dkh) is my favorite for steady system levels in the range I want: Ph 8.21 to 8.38 daily ,alkalinity a constant 9.5 dkh , magnesium around 1380ppm and calcium at 520ppm. The calcium is a bit high relative to sea water but does no harm.
I am able to keep good growth on a system loaded with sps by dosing limewater for top off( about 1% of water volume per day) via peristaltic pump in equal increments over a 24 hour period at a saturation of only 1.5 tsps of calcium hydroxide per gallon of ro water with only rare(every several months or so) doses of baking soda to boost alkalinity a half a point or so dkh.
Limewater has some advantages: it is 1part; it self purifies by precipitating out impurities into the slurry at the bottom; it precipitates some phosphate too by most accounts; it adds no extra chlorides;and, it is relatively inexpensive particularly when purchased from a bulk supplier like BRS(Bulk Reef Suppy) or as pickling lime Mrs Wages from WalMart..
However, it raises ph which may be a good thing or a bad thing depending on your system. Limewater at full saturation(2tsps of calcium hydroxide per gallon) has a ph of about 12.4. The hydroxide disassociates from the calcium in water and joins up with CO2 to form CO3(carbonate alkalinity),about 80% of which draws H+ from the water to form bicarbonate(HCO3). Ideally then the the carbonate/bicarbonate joins with the calcium to form calcium carbonate or skeletal mass for calcareous organisms like stony corals, clams, coraline,etc.Drawing down the H+ too far as when too much calcium hydroxide is dosed at once raises the ph and at some point usually around 8.6ph the water can no longer keep calcium and carbonate/bicarbonate in solution ,so they join up and fall out of solution as an abiotic precipitant ,calcium carbonate ( sand like material) or whitish caking material.
Ph spikes and the abiotic precipitation of calcium carbonate as "snow storms"of powdery white material in the tank , caked heaters ,clogged pumps, clogged reacators, clogged venturis and clumpy sand can result along with bouncing alkainity which is harmful to many corals particularly sps.
It is best to dose only the clear limewater as the slurry on the bottom contains precipitated impurities and perhaps more importantly undissolved calcium hydroxide which can cause overdosing if dosed when it is cloudy. No more than 1/4 tsp of calcium hydroxide powder per 50 gallons of system water volume per hour should be dosed to avoid ph spikes.
My system uses a 32 gallon brute garbage can full of ro water mixed with calcium hydroxide( at 1.5 tsp per gallon in my case) which is stirred manually with a length of pvc pipe.A peristaltic pump is used with the intake tube several inches off the bottom of the can to avoid dosing the slurry. I turn the pump off when adding new calcium hydroxide and ro water and wait 2 hours for settling before restarting to avoid dosing cloudy water. The pump I use ,a liter meter 3 by Spectrapure, is simpleto use but pricey. ther are other less costly pumps avaiable. I was lucky to get a good deal on a used liter meter and have had several years of trouble free service.On that pump you set the amount of liquid you wish to dose per day, in my case it's bout 18 liters. The pump doses that amount over a 24 hour period in 150 equal incremental squirts into the sump. Othe pumps work well in concert with $20 muti position digital timers which can turn them on and off to get a similar incremental effect.One brute can last about 5 days for my system. I could make the reservoir larger. In a losely covered reservoir without restirring limewater will hold it's strength for weeks . In fact restirring in other than a sealed nielsen type reactor will actually weaken it by drawing in CO2 from the surounding air and enocuraging precipitation in the reservoir.
There are other ways to dose limewater by dripping or using kalk stirrers /reactors. The later take less space and are often integrated into auto top off systems but do require periodic automatic restirring thoroughout the day since they hold little water and are cosntantly adding new water. Cloudy water dosing an be a problem with these and they are rather pricey ,unecessary and less useful than still reservoirs as simple as a bucket ,in my opinion.
Dripping by gravity can be easily done with just a bucket or jug placed over the sump with some airline tubing and an airline valve to control a drip rate.I dosed it this way for years without issuesbefore upgradingto the dosing pump.
Whatever method is used it is critical not to dose to much at once. Here is a copy of my post from another thread on dosing levels and the bucket design.
Mel, I used a salt bucket set above the sump for years before switching to a dosing pump and a brute garbage can. It worked fine. I rarely had to clean the plastic airline valve I used and when I did I just dropped it in vinegar for a few hours.
Whichever container you choose to use for dripping , put a small
(inch or two piece) of rigid airline tubing through the side of the container two inches or so from the bottom and smear a bead of plumber's goop around the outside rim of the tubing. Then push regular flexible airline tubing over the protruding nub of the rigid tube and run it to your dosing site. Put a plastic airline tube valve on the end of the flexible tube so you can adjust the drip rate.
This allows you to drip it without getting into any of the slurry(undissolved kalk and impurites) that may form at the bottom of the container which can clog things up.
Also keep the dosing end of the tube with the valve on the end five or six inches above the water . Submerging it or getting it splashed can cause the highly concentrated kalk to precipitate locally in the end of the tube.
As you probably know you should dose in a high flow area away from pump intakes.
Dose kalk over the longest practical period of time. With a dosing pump I dose in small increments over a 24 hour period. This not only keeps the ph constant but the salinity too.
At a minimum,avoid dosing more than 1/4 tsp of kalk powder in any given hour per 50gallons of system water volume( So, for example,1/2 gallon of solution at the full saturation rate of 1 tsp kalk/calcium hydroxide powder per 1/2 galllon of ro water would take a minimum of 4 hours to dose to a 50 gallon system; 1/2 gallon at only 1 tsp kalk would take a minimum of 2 hours.
Note , I used 1/2 gallon in the example since 1/2 gallon would be 1% of the total water volume , 50 gallons ,and 1% is about the average evaporation/top off rate. Obviously the evaporation rate will vary some from system to system.
Limiting dosing per hour to no more than 1/4 tsp per 50 gallons will make ph spikes and in tank abiotic precipitation very unlikely unless you start at very high ph.
Once you figure out how much you want to dose per hour,you can use a measuring cup , a clock and some math to adjust the airline valve to set the drip rate accordingly.
When setting up your drip,mix the powder into your ro water and let it settle for a few hours and dose only the clear limewater( kalk water). It will hold it's strength for weeks without restirring in a container with a lid on it even just a covered garbage can.
Restirring stirs up the slurry ,clouds the water and in a non airtight container draws in CO2 which will precipitate some of the kalk and weaken it.
__________________
Tom
Current Tank Info: 500g system consisting of a 120g reef sps mix
There are 4 mainstream ways to meet the system's needs for alkalinity and calcium. They are: waterchanges with high calcium alkalinity salt mixes; dosing a balanced calcium carbonate/bicarbonate mix via calcium reactor; 2 part dosing(aka balling method) with calcium chloride for calcium and baking soda or a commercial alkalinity mix for alkalinity;and last but not least limewater ( calcium hydroxide) dosing for a balanced mix of alkalinity and calcium.
Other than salt mix none add substantial magnesium. Commercial 2 part calcium additions may contain some but not likely enough to meet a system's needs for magnesium. So for now we'llset magnesium aside.
Water changes with a salt mix that is high in calcium and or alkalinity. This will work for some tanks but may cause undesireable rapid changes in the alkainity at the point of the water change which can be harmful to some corals. So somewhat frequent smaller , 25% changes are useful, in my opinion.
Calcium reactors dissolve aragonite (calcium carbonate) by passing acidified water high in carbonic acid(H2CO3) through media which is largely coral skeleton. CO2 which is injected into them quickly turns to carbonic acid dropping the ph to levels suitable to dissolve the media . Tuning them in can be tedious and most who use them experience chronically low ph since the effluent ph on calcium reactors is around 6.7 give or take 0.2. I used one for several years along with limewater dosing and was able to balance ph nicely but alkalinity was higher(12dkh+) than I liked when my system developed into a low nutrient system, so I kept the limewater and took the calcium reactor off line . Limewater alone with occasional boosting with baking soda works well for me. More about that later.
Two part dosing(aka the balling method).
Easy via pour in or dosing pumps.
Calcium chloride is used for the calcium. The chloride disassociates and adds to the chloride in the system. Not a big concern since chloride in sea water is about 19,000ppm, so the extra chloride form dosing is not likely to upset natural ratios of elements very much. Nonetheless, over a long period of time excess chlorides can build up particularly if regular water changes are not done or expensive special balling system salt mixes short on chloride are not used.
Commercial alkalinity supplements are primarily carbonate or bicarbonate plus some impurities/trace elements. 90% of alkalinity is seawater is bicarbonate or carbonate. Corals use bicarbonate. The rest is boron, and a slew of other things form some forms of phosphate to silicate. Baking soda unbaked is bicarbonate(HCO3) when baked it is carbonate (CO3). The proportion of carbonate to bicarbonate in nsw is about 1 to 5.
When I use two part dosing to supplement, I use baking soda and calcium chloride from brs. The commercial mixes are convenient for small systems though.
I've tried them all and limewater dosing from a still reservoir along with a high calcium / magnesium salt( Coralife in my case: magnesium 1400ppm, calcium 520ppm and alkalinity at 8dkh) is my favorite for steady system levels in the range I want: Ph 8.21 to 8.38 daily ,alkalinity a constant 9.5 dkh , magnesium around 1380ppm and calcium at 520ppm. The calcium is a bit high relative to sea water but does no harm.
I am able to keep good growth on a system loaded with sps by dosing limewater for top off( about 1% of water volume per day) via peristaltic pump in equal increments over a 24 hour period at a saturation of only 1.5 tsps of calcium hydroxide per gallon of ro water with only rare(every several months or so) doses of baking soda to boost alkalinity a half a point or so dkh.
Limewater has some advantages: it is 1part; it self purifies by precipitating out impurities into the slurry at the bottom; it precipitates some phosphate too by most accounts; it adds no extra chlorides;and, it is relatively inexpensive particularly when purchased from a bulk supplier like BRS(Bulk Reef Suppy) or as pickling lime Mrs Wages from WalMart..
However, it raises ph which may be a good thing or a bad thing depending on your system. Limewater at full saturation(2tsps of calcium hydroxide per gallon) has a ph of about 12.4. The hydroxide disassociates from the calcium in water and joins up with CO2 to form CO3(carbonate alkalinity),about 80% of which draws H+ from the water to form bicarbonate(HCO3). Ideally then the the carbonate/bicarbonate joins with the calcium to form calcium carbonate or skeletal mass for calcareous organisms like stony corals, clams, coraline,etc.Drawing down the H+ too far as when too much calcium hydroxide is dosed at once raises the ph and at some point usually around 8.6ph the water can no longer keep calcium and carbonate/bicarbonate in solution ,so they join up and fall out of solution as an abiotic precipitant ,calcium carbonate ( sand like material) or whitish caking material.
Ph spikes and the abiotic precipitation of calcium carbonate as "snow storms"of powdery white material in the tank , caked heaters ,clogged pumps, clogged reacators, clogged venturis and clumpy sand can result along with bouncing alkainity which is harmful to many corals particularly sps.
It is best to dose only the clear limewater as the slurry on the bottom contains precipitated impurities and perhaps more importantly undissolved calcium hydroxide which can cause overdosing if dosed when it is cloudy. No more than 1/4 tsp of calcium hydroxide powder per 50 gallons of system water volume per hour should be dosed to avoid ph spikes.
My system uses a 32 gallon brute garbage can full of ro water mixed with calcium hydroxide( at 1.5 tsp per gallon in my case) which is stirred manually with a length of pvc pipe.A peristaltic pump is used with the intake tube several inches off the bottom of the can to avoid dosing the slurry. I turn the pump off when adding new calcium hydroxide and ro water and wait 2 hours for settling before restarting to avoid dosing cloudy water. The pump I use ,a liter meter 3 by Spectrapure, is simpleto use but pricey. ther are other less costly pumps avaiable. I was lucky to get a good deal on a used liter meter and have had several years of trouble free service.On that pump you set the amount of liquid you wish to dose per day, in my case it's bout 18 liters. The pump doses that amount over a 24 hour period in 150 equal incremental squirts into the sump. Othe pumps work well in concert with $20 muti position digital timers which can turn them on and off to get a similar incremental effect.One brute can last about 5 days for my system. I could make the reservoir larger. In a losely covered reservoir without restirring limewater will hold it's strength for weeks . In fact restirring in other than a sealed nielsen type reactor will actually weaken it by drawing in CO2 from the surounding air and enocuraging precipitation in the reservoir.
There are other ways to dose limewater by dripping or using kalk stirrers /reactors. The later take less space and are often integrated into auto top off systems but do require periodic automatic restirring thoroughout the day since they hold little water and are cosntantly adding new water. Cloudy water dosing an be a problem with these and they are rather pricey ,unecessary and less useful than still reservoirs as simple as a bucket ,in my opinion.
Dripping by gravity can be easily done with just a bucket or jug placed over the sump with some airline tubing and an airline valve to control a drip rate.I dosed it this way for years without issuesbefore upgradingto the dosing pump.
Whatever method is used it is critical not to dose to much at once. Here is a copy of my post from another thread on dosing levels and the bucket design.
Mel, I used a salt bucket set above the sump for years before switching to a dosing pump and a brute garbage can. It worked fine. I rarely had to clean the plastic airline valve I used and when I did I just dropped it in vinegar for a few hours.
Whichever container you choose to use for dripping , put a small
(inch or two piece) of rigid airline tubing through the side of the container two inches or so from the bottom and smear a bead of plumber's goop around the outside rim of the tubing. Then push regular flexible airline tubing over the protruding nub of the rigid tube and run it to your dosing site. Put a plastic airline tube valve on the end of the flexible tube so you can adjust the drip rate.
This allows you to drip it without getting into any of the slurry(undissolved kalk and impurites) that may form at the bottom of the container which can clog things up.
Also keep the dosing end of the tube with the valve on the end five or six inches above the water . Submerging it or getting it splashed can cause the highly concentrated kalk to precipitate locally in the end of the tube.
As you probably know you should dose in a high flow area away from pump intakes.
Dose kalk over the longest practical period of time. With a dosing pump I dose in small increments over a 24 hour period. This not only keeps the ph constant but the salinity too.
At a minimum,avoid dosing more than 1/4 tsp of kalk powder in any given hour per 50gallons of system water volume( So, for example,1/2 gallon of solution at the full saturation rate of 1 tsp kalk/calcium hydroxide powder per 1/2 galllon of ro water would take a minimum of 4 hours to dose to a 50 gallon system; 1/2 gallon at only 1 tsp kalk would take a minimum of 2 hours.
Note , I used 1/2 gallon in the example since 1/2 gallon would be 1% of the total water volume , 50 gallons ,and 1% is about the average evaporation/top off rate. Obviously the evaporation rate will vary some from system to system.
Limiting dosing per hour to no more than 1/4 tsp per 50 gallons will make ph spikes and in tank abiotic precipitation very unlikely unless you start at very high ph.
Once you figure out how much you want to dose per hour,you can use a measuring cup , a clock and some math to adjust the airline valve to set the drip rate accordingly.
When setting up your drip,mix the powder into your ro water and let it settle for a few hours and dose only the clear limewater( kalk water). It will hold it's strength for weeks without restirring in a container with a lid on it even just a covered garbage can.
Restirring stirs up the slurry ,clouds the water and in a non airtight container draws in CO2 which will precipitate some of the kalk and weaken it.
__________________
Tom
Current Tank Info: 500g system consisting of a 120g reef sps mix
Steve Canyon
New member
Thanks Tom. I feel like I pick up a little more everytime you post. I wish I had what it took to absorb and associate everything everytime. Unfortunately, I don't. So please continue to re-iteriate to those of us that just can't pick it all up the first few times around. I know it's nothing more than 9th grade chemistry, but I haven't had reason to even think about it for 37 years!
PM coming your way.
PM coming your way.
jfl14609
Active member
I'm glad to hear that. I try to make it all a littlle clearer and easier to take in.The vast amount information and misinformation that goes with reef tanks is hard to get your head around.Some posts and manufacturer's product gibberish often make it even harder Sorry about the headache. Thanks again, glad th post was helpful.
Well to be perfectly honest I like to keep things as simplfied as possible.Im not big on gagets ,chemicals or test kits.I use limewater and baking soda and recently started to test calcium.It was low so I brought the level up with calcium cloride ,nothing special just kent marine off the shelf stuff.
I do use a nilsen reactor but as noted its probably unnecessary and pricey for most.It was sorta old schoolish thinking and having 10 year gap in reefkeeping was what I knew at the time.
More up to date info. I learned since coming to this forum was that Gfo can lower the alk and that higher levels of phosphate can give you the illusion that your tank cant be maintained with kalkwasser alone.
Just some thoughts, you can use a ph probe or a high range ph kit to test the saturation of kalkwasser if your not sure.Saturated as (tmc)noted has a ph of aroun 12 so it doesn't have to look milky to be saturated.
I do use a nilsen reactor but as noted its probably unnecessary and pricey for most.It was sorta old schoolish thinking and having 10 year gap in reefkeeping was what I knew at the time.
More up to date info. I learned since coming to this forum was that Gfo can lower the alk and that higher levels of phosphate can give you the illusion that your tank cant be maintained with kalkwasser alone.
Just some thoughts, you can use a ph probe or a high range ph kit to test the saturation of kalkwasser if your not sure.Saturated as (tmc)noted has a ph of aroun 12 so it doesn't have to look milky to be saturated.
Hi Graves,
I don't fully understand part of this:
"More up to date info. I learned since coming to this forum was that Gfo can lower the alk and that higher levels of phosphate can give you the illusion that your tank cant be maintained with kalkwasser alone."
Yep gfo will lower alkalinity a bit ,since it some calcium carbonate will precipitate on it.I found it hard to use( clumping when I ran high alkalinity (12dkh+). It works much better and longer with my alk at around 9.5.
I test PO4 daily with the hanah and it's consistently low in my system(0.04ppm) and I still run just limewater for calcium and alkalinity. I use gfo and carbon dosing too.
I think when you say "illusion" you mean that with high PO4 coral calcification is inhibited and as a consequence little to no alkalinity and/or calcium is used. That is certainly true.
High PO4 can be offset to some degree with higher alkalinity (in the teens) but when you drop it some corals will often suffer stn unless the alkalinity is adjusted downward as well.
I don't think there is anything inherently wrong with a kalk stirrer/reactor, neilsen type; it's just easier to get clear limewater consistently from a still reservoir for me.
I don't fully understand part of this:
"More up to date info. I learned since coming to this forum was that Gfo can lower the alk and that higher levels of phosphate can give you the illusion that your tank cant be maintained with kalkwasser alone."
Yep gfo will lower alkalinity a bit ,since it some calcium carbonate will precipitate on it.I found it hard to use( clumping when I ran high alkalinity (12dkh+). It works much better and longer with my alk at around 9.5.
I test PO4 daily with the hanah and it's consistently low in my system(0.04ppm) and I still run just limewater for calcium and alkalinity. I use gfo and carbon dosing too.
I think when you say "illusion" you mean that with high PO4 coral calcification is inhibited and as a consequence little to no alkalinity and/or calcium is used. That is certainly true.
High PO4 can be offset to some degree with higher alkalinity (in the teens) but when you drop it some corals will often suffer stn unless the alkalinity is adjusted downward as well.
I don't think there is anything inherently wrong with a kalk stirrer/reactor, neilsen type; it's just easier to get clear limewater consistently from a still reservoir for me.
I received an intersting pm on a related topic PO4. Between teh length of the senders pm and the reply ,the pm wouldn't work so I'll post he reply here. The sender can identify his/her self if they wish. The tank in question has very high PO4 and supports many fish and mostly leather corals with some lps and montis and lots of sun corals.
Stony corals(lps and sps,more so sps in my experience) are inhibitted by high PO4, ie over 0.1ppm . You have 25x that amount. PO4 joins a forming calcium carbonate crystal in place of calcium and stops the crystal from contiuing to grow. Gfo will exhaust rapidly( a day or so) at those levels and you may need to use a lot of it over time($) at about 2grms per gallon each time you change it. It works much better in a reactor; I prefer the 2 little fishes reactor. With levels that high a lot has probably stuck to the rock and will leach back as the PO4 in the water is reduced. It may take months to a year before you clear it out. I'd look into the thread on regenerating gfo in the reef chemistry forum to make this economically practical. Otherwise, you might try lanthanum chloride with proper filtering. Techniques and details for this method are in Gary's thread on it.
Most of your corals can do fine with the high PO4. I'd worry about the montis and to a lesser extent the lps depending on what they are. Nuisance algae may become a problem though. Beware of reducing the PO4 too precipitously, some of your corals ,particularly the non photo synthetics may need time to adjust to lowered levels.I'd, personally go all out down to about 0.25ppm then go slowly below that.
Yes. I would invest in a refractometer. Sg is one of the most critical parameters.
Go easy with the vodka dosing.
Stony corals(lps and sps,more so sps in my experience) are inhibitted by high PO4, ie over 0.1ppm . You have 25x that amount. PO4 joins a forming calcium carbonate crystal in place of calcium and stops the crystal from contiuing to grow. Gfo will exhaust rapidly( a day or so) at those levels and you may need to use a lot of it over time($) at about 2grms per gallon each time you change it. It works much better in a reactor; I prefer the 2 little fishes reactor. With levels that high a lot has probably stuck to the rock and will leach back as the PO4 in the water is reduced. It may take months to a year before you clear it out. I'd look into the thread on regenerating gfo in the reef chemistry forum to make this economically practical. Otherwise, you might try lanthanum chloride with proper filtering. Techniques and details for this method are in Gary's thread on it.
Most of your corals can do fine with the high PO4. I'd worry about the montis and to a lesser extent the lps depending on what they are. Nuisance algae may become a problem though. Beware of reducing the PO4 too precipitously, some of your corals ,particularly the non photo synthetics may need time to adjust to lowered levels.I'd, personally go all out down to about 0.25ppm then go slowly below that.
Yes. I would invest in a refractometer. Sg is one of the most critical parameters.
Go easy with the vodka dosing.
Hi tom,
One of your responses in a thread awhile back you mentioned phosphate could take the place of a Calcium ion in a precipitate event.Leading me to assume the drop in alk might be witnessed.The original poster was asking about low Mg and was using a 2 part.
Hmmmm, not sure but am I wrong to think the higher ph of limewater(12-ish) ,although dripped and the overall aquarium ph isn't spiked but at the "site" lower alk as CaPo4 (calcium phosphate).?
One of your responses in a thread awhile back you mentioned phosphate could take the place of a Calcium ion in a precipitate event.Leading me to assume the drop in alk might be witnessed.The original poster was asking about low Mg and was using a 2 part.
Hmmmm, not sure but am I wrong to think the higher ph of limewater(12-ish) ,although dripped and the overall aquarium ph isn't spiked but at the "site" lower alk as CaPo4 (calcium phosphate).?
>>>
Yeah, I know, I just realize that it doesn't matter.saturated is it and supersaturated (milky limerwater) is not better and actually not a good thing. In its day it was generaly thought to be a safe practice.A bit more to it as far as why Im using it but not trying to derail another thread.
FWIW- Dont know how it happens but I seem to be one for derailing threads ,sorry jeff. unintenional but like I said , I cant be the only one in wonderment.
The formation of calcium phosphate,Ca3(PO4)2 would have no direct effect on alkalinity. It might use a little calcium though.
Indirectly, by discouraging calcium carbonate precipitation it would reduce alkainity (carbonate/bicabonate) consumption keeping alkalinity higher than would otherwise be the case.
Yes PO4 may take the place of a calcium ion in a forming calcium carbonate crystal in some cases halting it's growth. It binds to calcium carbonate most often at a ph of 8.4 with higher or lower ph conditions lessening the occurences of binding .So the 12.4 ph effluent's effect on ph in the water at the dosing site might or might not not be a significant factor in the amount of Ca phosphate precipitation depending on the actual ph value achieved at the dosing site.
If the clcium carbonate crystal keeps growing after binding some inorganic phopsphate it can capture the PO4. If it stops growing it is thought that the tiny calcium phosphate crystal, Ca3(PO4)2, may be covered with organics and skimmed out reducing some PO4 from the aquarium. This last event suggesting potential PO4 removal via precipitation then organic growth and then by the skimming is a likely and logical but yet untested hypothesis.
This binding of PO4 to calcium carbonate may also occur in the aquarium to surfaces such as the live rock aragonite substrates and other calcium carbonate surfaces .
All in all excess PO4 discourages precipitation of calcium carbonate both bioticly and abioticly . Less precipitation of carbonate/ bicarbonate tends to keep alkalinity levels higher not make them lower.
In stony corals exposed to excessive PO4, biotic precipitation is inhibited in two ways:
The presence of phosphate in the coral's ECF, extracytopasmic fluid,inhibits the corals ability to guide the growth of skeletal mass.
The phosphate will also be present on the foming crystals themselves further inhibiting calcification.
For perspective it is worth noting that a field study established that exposure to 0.19ppm of inorganic phosphate for 3 hours pr day inhibited coral calcification rates on a patch reef of the Great Barrier Reef by 43% per Randy Farely's article on phosphate. So reducing PO4 species to low levels is a big key especially with sps and many other stony corals.
I don't understand your second question. If you mean the dosing site yes ph may be higher momentarily in a high flow area. PO4 precipitation is thought to occur but is not a proven outcome as far as I know.
Graves , I hope I've answered your questions. Not really sure since I didn't see the quotes.
Regarding PO4 reduction from limewater dosing. Yes it seems that at higher levels some reduction would be observable because there would be more calcium carbonate around for binding but using limewater to reduce PO4 is not a good strategy, in my opinion, since its effects are ph dependent and likely to be minimal but whatever it does to reduce PO4 is a plus nonetheless.
Much of this discussion has centered on alkalinity. It's probably useful to review what it is.
It is not a thing. It is a measure of a number of things which have the ability to absorb H+protons.For seawater it is a measure of how much H+ can be absorbed before all of the carbonate and bicarbonate(CO3/HCO3) in the water can be converted to carbonic acid ( H2CO3).This would result in a ph of about 4.2.
Total alkalinity in sea water includes the following elements and their relative contributions to alkalinity:
"Chemical Species Relative Contribution To Alkalinity
HCO3- (bicarbonate) 89.8
CO3-- (carbonate) 6.7
B(OH)4- (borate) 2.9
SiO(OH)3- (silicate) 0.2
MgOH+ (magnesium monohydroxylate) 0.1
OH- (hydroxide) 0.1
HPO4-- and PO4--- (phosphate) 0.1
Other species can also contribute measurably to alkalinity in seawater in certain situations, such as anoxic regions. These would include NH4+ and HS- .
In reef tanks, some of these species can be present in substantially higher concentrations than in seawater. For example, a reef tank with a phosphate concentration of 0.5 ppm will have a higher contribution from phosphate (2.5 times the value shown in the table)." From the linked article by Randy Homes Farely:
http://www.advancedaquarist.com/issues/feb2002/chemistry.htm
Corals only use HCO3, CO3 is readily converted to HCO3 continuously. Together they make up about 90% of total alkalinity which is what we measure with test kits and use as a surrogate measure for bicarbonate(HCO3).
So where is the carbonate/bicarbonate in limewater( clacium hydroxide Ca(OH)2)? There isn't any. The hydroxide joins up with CO2 to form CO3(carbonate) and HCO3(bicarbonate) via a number of intermediate steps not worth going through here.
So, yes PO4 does contribute to alkalinity but the contribution is very small and of no use to calcareous organisms. Dropping it rapidly form very high levels may have some very small likely unmeasureable effect on total alkalinity. More importantly increased precipitation of calcium carbonate may occur uninhibited by PO4 . This increased precipitation of calcium carbonate as skeletal mass and/or abioitc precipitation will reduce the carbonate/bicarbonate and the total alkalinity to a greater extent than the PO4 precipitation itself or removal itself.
Regarding PO4 reduction from limewater dosing. Yes it seems that at higher levels some reduction would be observable because there would be more calcium carbonate around for binding but using limewater to reduce PO4 is not a good strategy, in my opinion, since its effects are ph dependent and likely to be minimal but whatever it does to reduce PO4 is a plus nonetheless.
Much of this discussion has centered on alkalinity. It's probably useful to review what it is.
It is not a thing. It is a measure of a number of things which have the ability to absorb H+protons.For seawater it is a measure of how much H+ can be absorbed before all of the carbonate and bicarbonate(CO3/HCO3) in the water can be converted to carbonic acid ( H2CO3).This would result in a ph of about 4.2.
Total alkalinity in sea water includes the following elements and their relative contributions to alkalinity:
"Chemical Species Relative Contribution To Alkalinity
HCO3- (bicarbonate) 89.8
CO3-- (carbonate) 6.7
B(OH)4- (borate) 2.9
SiO(OH)3- (silicate) 0.2
MgOH+ (magnesium monohydroxylate) 0.1
OH- (hydroxide) 0.1
HPO4-- and PO4--- (phosphate) 0.1
Other species can also contribute measurably to alkalinity in seawater in certain situations, such as anoxic regions. These would include NH4+ and HS- .
In reef tanks, some of these species can be present in substantially higher concentrations than in seawater. For example, a reef tank with a phosphate concentration of 0.5 ppm will have a higher contribution from phosphate (2.5 times the value shown in the table)." From the linked article by Randy Homes Farely:
http://www.advancedaquarist.com/issues/feb2002/chemistry.htm
Corals only use HCO3, CO3 is readily converted to HCO3 continuously. Together they make up about 90% of total alkalinity which is what we measure with test kits and use as a surrogate measure for bicarbonate(HCO3).
So where is the carbonate/bicarbonate in limewater( clacium hydroxide Ca(OH)2)? There isn't any. The hydroxide joins up with CO2 to form CO3(carbonate) and HCO3(bicarbonate) via a number of intermediate steps not worth going through here.
So, yes PO4 does contribute to alkalinity but the contribution is very small and of no use to calcareous organisms. Dropping it rapidly form very high levels may have some very small likely unmeasureable effect on total alkalinity. More importantly increased precipitation of calcium carbonate may occur uninhibited by PO4 . This increased precipitation of calcium carbonate as skeletal mass and/or abioitc precipitation will reduce the carbonate/bicarbonate and the total alkalinity to a greater extent than the PO4 precipitation itself or removal itself.
Great,after reading your response this morning I wonder if theres any study done linking reefkeeping with cancer,I just started smoking.
All kidding aside,yes my questions are well answered,very informative.thank you.
( Actualy prior to your last post and reviewing this whole thread you had already answered my questions but I guess I missed it.)
I gota take a breather and absorb from all the posts lately.As the others made note of Im no chemist either.
Thanks again-
All kidding aside,yes my questions are well answered,very informative.thank you.
( Actualy prior to your last post and reviewing this whole thread you had already answered my questions but I guess I missed it.)
I gota take a breather and absorb from all the posts lately.As the others made note of Im no chemist either.
Thanks again-
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Original poster asked about pics of setups.Heres how mine is setup.
Output of ro/di goes directly to this bucket,inside is an auto float valve
<a href="http://s298.photobucket.com/albums/mm255/gravesj1s/?action=view¤t=314.jpg" target="_blank"><img src="http://i298.photobucket.com/albums/mm255/gravesj1s/314.jpg" border="0" alt="Photobucket"></a>
Aqualifter pump .Note the 2 airlines ,one draws water from the bucket the other goes into the kalkreactor.Its output is restricted with a simple airline valve, cheap and works well (12.00 bucks
<a href="http://s298.photobucket.com/albums/mm255/gravesj1s/?action=view¤t=415.jpg" target="_blank"><img src="http://i298.photobucket.com/albums/mm255/gravesj1s/415.jpg" border="0" alt="Photobucket"></a>
Kalkreactor (note the black tape I put on the sump and water makeup.I like the aquamedic over the other types that use powerheads to mix.It mixes so slowly that none of the undisolved or settled out stuff gets in the column of the reactor.
<a href="http://s298.photobucket.com/albums/mm255/gravesj1s/?action=view¤t=417.jpg" target="_blank"><img src="http://i298.photobucket.com/albums/mm255/gravesj1s/417.jpg" border="0" alt="Photobucket"></a>
Black tape and note holding vat.I'd only be able to use half the bucket without the aqualifter pump.
Second,The ro output ph is around 6 and without the reactor my alk drops to below 7dkh.So I need the reactor to get better dissolution.With it Im able to maintain levels of CA.490 and 8-8.5 dkh.(We have a fireplace so evaporation varys and reason for 8-8.5 dkh
Output of ro/di goes directly to this bucket,inside is an auto float valve
<a href="http://s298.photobucket.com/albums/mm255/gravesj1s/?action=view¤t=314.jpg" target="_blank"><img src="http://i298.photobucket.com/albums/mm255/gravesj1s/314.jpg" border="0" alt="Photobucket"></a>
Aqualifter pump .Note the 2 airlines ,one draws water from the bucket the other goes into the kalkreactor.Its output is restricted with a simple airline valve, cheap and works well (12.00 bucks
<a href="http://s298.photobucket.com/albums/mm255/gravesj1s/?action=view¤t=415.jpg" target="_blank"><img src="http://i298.photobucket.com/albums/mm255/gravesj1s/415.jpg" border="0" alt="Photobucket"></a>
Kalkreactor (note the black tape I put on the sump and water makeup.I like the aquamedic over the other types that use powerheads to mix.It mixes so slowly that none of the undisolved or settled out stuff gets in the column of the reactor.
<a href="http://s298.photobucket.com/albums/mm255/gravesj1s/?action=view¤t=417.jpg" target="_blank"><img src="http://i298.photobucket.com/albums/mm255/gravesj1s/417.jpg" border="0" alt="Photobucket"></a>
Black tape and note holding vat.I'd only be able to use half the bucket without the aqualifter pump.
Second,The ro output ph is around 6 and without the reactor my alk drops to below 7dkh.So I need the reactor to get better dissolution.With it Im able to maintain levels of CA.490 and 8-8.5 dkh.(We have a fireplace so evaporation varys and reason for 8-8.5 dkh
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