Dosing Nitrate to reduce Phosphate

[swcc]

Won't that also increase the P? The whole point is to get lower P levels not higher

no... I have been saying that over and again with my posts in this thread.

 

[swcc]

No, maybe I was unclear. The idea is that with excess carbon and nitrogen, as soon as phosphate appears it will be taken up by bacteria(phosphate limited system). I detect trace amounts of nitrate on the test with zero phosphate in my current steady state. Before this I would always show zero nitrate but have some measurable phosphate. So far, maintaining this trace amount has only been with periodic dosing of small amounts of nitrate.

I don't actually know if I have excess carbon, just right, or too much. Based on the guides, I should be just right since I get light algae growth on the glass, none on the rocks, but no white bacterial films. I add additional doses of vinegar or vodka from time to time and don't see any visible reaction(like a major bloom), so I don't think I should go any higher with my dose than the ~50ml of white vinegar I add now.

Normally feeding the tank adds both nitrate and phosphate to the water in close to the proper ratio, and the bacteria break this down, but as most people experience, phosphates build up eventually - thats why most people use GFO to scavenge this bit of phosphate. I just want to maintain the ratio or slightly tilt it toward nitrate rather than phosphate.

I hate to dose anything periodically, because its too easy to forget to do it. I would love to add a trace amount of nitrate to my carbon source which is dosed in automatically. This trace amount would equal the amount I add periodically, just spread out over multiple doses. Im still dialing in the exact amount I need to add to keep the Nitrate slightly positive.

guidelines are just that... guidelines.. there is no set in stone dosing quantifier that works for everyone... you are still going left and around the block to get to the neighbor on your right... there is no need to add something back if you are overdoing the removal of that very thing. you simply adjust so your not overdoing it anymore. This is what becoming an experience reefer and great husbandry is all about. It is like dosing two part for alk and cal... if you dose too much of one...you cut back and find the balance to get it just right.. you don't add more of the other to make up for the mistake of too much of one.

 

[mhucasey]

I actually have a substantial amount of experience in this hobby, starting my first reef tank with the berlin method back in 1991. I am obsessive about cleaning, testing, and maintaining my system, i automate not out of laziness but to increase stability. My day job is as an automation engineer in a biotech facility - and the automation is not for speed or cost reduction, its for repeatability and reliability.

Many people in the hobby endeavor to keep their phosphate levels low - and quite a large percentage use GFO. GFO has its issues as well, for me the issue was that its removal of phosphate is not very steady - it does most of its job quickly(first 24 hours or so) then its removal of additional phosphate is less effective. There are anecdotal claims of negative effects from too much GFO used on everything from clams to corals.

One of the challenges of this tank was maintaining a lot of fish as well as many SPS. I also believe(from experience and research) that well- fed fish are less susceptible to disease. My display tank has a working volume of about 83 gallons, total system volume is ~106 gallons, and I have 28 fish, including 8 anthias. I had a newly added psudochromis develop a major infection where its pectoral fins were pretty much gone and the tail was rotted away - that fish ate and ate and is currently 100% helathy with all fins regrown.

There are many ways to do things in this hobby and we can arrive at similar results. I remember being lectured by aquarium store owners back in 1992 that my reef was going to collapse and everything was going to die since I had removed all the "essential" filtration equipment such as bio-balls, resins, filter floss, etc. and was going with a skimmer and kalkwasser topoff only. I personally feel that we still have much to learn about Nitrate and Phosphate and the aquarium environment and look forward to that.

FYI, some one who doses calcium nitrate that I found impressive is jawsee:

http://reefkeeping.com/joomla/index.php/current-issue/article/71-tank-of-the-month


A quote from him in response to someone asking about calcium Nitrate. They had assumed he used Zeovit:
"Hi,i have no zeovit sytem do i use some products from the range,when i used it i started whit a 1 liter bottle wher i put in 10 grams,i dosed then until i can measure no3 at a range of 1-2,most of the time aproc 50 ml a day was fine for me,if you put in too much your glas becomes green and algae grow faster,this is my personal doses and for my tank it did well,start low and look at your animals"

 

[RickMartin]

no... I have been saying that over and again with my posts in this thread.

IME That's not true. In fact I would almost say the opposite of what you claim. That if you let more detritus build up you will end with higher phosphates than nitrates. The bacteria may break down detritus and release a higher ratio of N to P as you claimed in a previous post and that in turn will be used by bacteria. But Nitrates still get processed and released as nitrogen removing it from the system.
And this is exactly what I experienced when I had shoulder surgery this summer and could not keep my aquarium as clean as I normally do. P got higher and N stayed at 0 (or tltr)

 

[mhucasey]

RickMartin,
I agree. The goal is to remove as much detritus and keep as much clean as possible to slow this process down. No matter how obsessive people are about removing detritus from the system(remember/ever seen starboard Bare bottom reefs?) it eventually will happen where phosphate will build up. When you add lots of frozen food like I do, its just that much faster. Re-ballancing with a bit of nitrate is one possible solution to eliminate the build-up.

 

[swcc]

IME That's not true. In fact I would almost say the opposite of what you claim. That if you let more detritus build up you will end with higher phosphates than nitrates. The bacteria may break down detritus and release a higher ratio of N to P as you claimed in a previous post and that in turn will be used by bacteria. But Nitrates still get processed and released as nitrogen removing it from the system.
And this is exactly what I experienced when I had shoulder surgery this summer and could not keep my aquarium as clean as I normally do. P got higher and N stayed at 0 (or tltr)

it will depend on the amount of detritus as I suggested earlier.. so your confusing a tank extremely clean vs an untouched substrate tank where the detritus levels are already elevated. the situation is: the tank is so clean, bacteria levels are very low and phosphate rises due to being too clean and importing phosphate through feeding... then there are those tanks that are dirty and phosphate has risen due to accumulation and overabundance even with large bacterial activity... there is a balance between the two.. most tanks experience the rise in Phosphate because it is too dirty and measures were taken with filtration to reduce nitrate and the problems associated with moving to an eutrophic state.. true oligotrophic tanks are so clean that nitrate is never seen and phosphate can develop because of lack of significant levels of biological filtration... over driving biological filtration becomes an issue as the nitrate will reduce above and beyond phosphate levels. In effect to control phosphate, all one needs to do is run a strong skimmer that is not building up lots of skimmate in the neck(not too dry) and siphon substrate of detritus. Been dong it this way for a long time... I have never needed to implement any phosphate reduction methods, and indeed dosed carbon through the 'uglies' phase on my current tank as I was anxious and did not cure(cook) my rock long enough... thus I implemented vodka dosing to increase the bacterial element through that phase. Now... currently... the filtration is skimmer only with detritus removal and changing out about 10% of my water monthly. zero on nitrate and phosphate testing.

 

[swcc]

RickMartin,
I agree. The goal is to remove as much detritus and keep as much clean as possible to slow this process down. No matter how obsessive people are about removing detritus from the system(remember/ever seen starboard Bare bottom reefs?) it eventually will happen where phosphate will build up. When you add lots of frozen food like I do, its just that much faster. Re-ballancing with a bit of nitrate is one possible solution to eliminate the build-up.

you are right that overfeeding a system will result in a phosphate increase... yet the situation is really dependent upon: effective removal through skimmer size/processing speed...
more air may not be better vs strong air to water throughput and speed of removal. I am a strong feeder too... I just run a great skimmer to pull the rise in organics fast and efficiently and the skimmer is setup to wet skim a more tea colored(brown/medium brown vs black) skimmate.

 

[mhucasey]

I think the impasse we are having is that you don't carbon dose. I would never add Nitrate if I wasn't carbon dosing - this idea only works when relying on bacterial uptake. This method has no applicability for you.

I heartily agree that an effective skimmer is critical for elimination of wastes. I currently run a Eshopps S-200 cone skimmer which is rated for more than double my display volume. The pump on mine is a Sicce PSK-1000 rated for 870 gallons per hour. That thing pulls a lot of gunk out each day.

There is a difference between feeding heavily and overfeeding. I defrost the equivalent of 5 cubes each mysis and garlic brine shrimp and two oyster eggs cubes in a ~ 6 oz squirt bottle(like a mustard bottle). To this I add a few drops garlic extract, and 6 drops vitamins, and fresh ASW. I use the bottle to add 3-5 small squirts to the mass of fish at the top of the tank.

The whole feeding takes about 40 seconds and I repeat this 4-5 times a day. The bottle lasts about 2 days. I would feed less times a day, but i have Anthias and they have small stomachs. Anthias require more frequent feedings to stay disease free(and the other fish come along for the free meal).

Nothing is wasted food wise. This to me is a "heavy feeding". Food that is added in a big dose and that ends up all over the bottom is "overfeeding".

 

[swcc]

I think the impasse we are having is that you don't carbon dose. I would never add Nitrate if I wasn't carbon dosing - this idea only works when relying on bacterial uptake. This method has no applicability for you.

I heartily agree that an effective skimmer is critical for elimination of wastes. I currently run a Eshopps S-200 cone skimmer which is rated for more than double my display volume. The pump on mine is a Sicce PSK-1000 rated for 870 gallons per hour. That thing pulls a lot of gunk out each day.

There is a difference between feeding heavily and overfeeding. I defrost the equivalent of 5 cubes each mysis and garlic brine shrimp and two oyster eggs cubes in a ~ 6 oz squirt bottle(like a mustard bottle). To this I add a few drops garlic extract, and 6 drops vitamins, and fresh ASW. I use the bottle to add 3-5 small squirts to the mass of fish at the top of the tank.

The whole feeding takes about 40 seconds and I repeat this 4-5 times a day. The bottle lasts about 2 days. I would feed less times a day, but i have Anthias and they have small stomachs. Anthias require more frequent feedings to stay disease free(and the other fish come along for the free meal).

Nothing is wasted food wise. This to me is a "heavy feeding". Food that is added in a big dose and that ends up all over the bottom is "overfeeding".

I did carbon dose... the point I am making in regards to doing it is to balance it so one does not strip all the nitrate and end up with extra phosphate. Essentially I carbon dosed very little(never got over 1ml with my 60 gal)... now with that dose I ran into the same situation as trace po4 was showing up when testing..In my particular situation because I run my tank very clean, I simply eased up on the amount of detritus I pulled every couple weeks which raised bacteria processes a bit and from that the po4 went away.
In your situation, my first though is... lessen the vinegar dose a little and let the nitrate rise to a trace reading (like it is with the nitrate dosing)... the po4 will also go away this way as well. And again the reason I suggest this is this way the bacterial counts become less and you suffer less effect from having the higher bacteria counts... So, lower bacteria, alk stays more stable and ph can be higher. The dosing has effects most do not think about and simply adjust... there is still a cause and effect to adding nutrients to reduce other nutrients... and adding nutrient to replace previously reduced nutrients is not a common sense approach. Your adding nitrate because your vinegar dosing is reducing too much already occurring nitrate... where does that make any logical sense?

 

[gbru316]

... balance it so one does not strip all the nitrate and end up with extra phosphate. You're adding nitrate because your vinegar dosing is reducing too much already occurring nitrate... where does that make any logical sense?

I'm inclined to agree. If you keep adding things you've previously taken out, you're spending time and money chasing a problem that you, yourself, created.

In my career, I've seen this cycle many times. Instead of realizing and correcting the initial problem, a course of action is taken that creates more problems, then those problems are chased, which often causes OTHER problems, which mistakenly get added as "symptoms" of the original problem when they are actually unrelated. This cycle rarely ends up fixing the original problem.

 

[ReefKeeper64]

I actually have a substantial amount of experience in this hobby, starting my first reef tank with the berlin method back in 1991. I am obsessive about cleaning, testing, and maintaining my system, i automate not out of laziness but to increase stability. My day job is as an automation engineer in a biotech facility - and the automation is not for speed or cost reduction, its for repeatability and reliability.

Many people in the hobby endeavor to keep their phosphate levels low - and quite a large percentage use GFO. GFO has its issues as well, for me the issue was that its removal of phosphate is not very steady - it does most of its job quickly(first 24 hours or so) then its removal of additional phosphate is less effective. There are anecdotal claims of negative effects from too much GFO used on everything from clams to corals.

One of the challenges of this tank was maintaining a lot of fish as well as many SPS. I also believe(from experience and research) that well- fed fish are less susceptible to disease. My display tank has a working volume of about 83 gallons, total system volume is ~106 gallons, and I have 28 fish, including 8 anthias. I had a newly added psudochromis develop a major infection where its pectoral fins were pretty much gone and the tail was rotted away - that fish ate and ate and is currently 100% helathy with all fins regrown.

There are many ways to do things in this hobby and we can arrive at similar results. I remember being lectured by aquarium store owners back in 1992 that my reef was going to collapse and everything was going to die since I had removed all the "essential" filtration equipment such as bio-balls, resins, filter floss, etc. and was going with a skimmer and kalkwasser topoff only. I personally feel that we still have much to learn about Nitrate and Phosphate and the aquarium environment and look forward to that.

FYI, some one who doses calcium nitrate that I found impressive is jawsee:

http://reefkeeping.com/joomla/index.php/current-issue/article/71-tank-of-the-month


A quote from him in response to someone asking about calcium Nitrate. They had assumed he used Zeovit:
"Hi,i have no zeovit sytem do i use some products from the range,when i used it i started whit a 1 liter bottle wher i put in 10 grams,i dosed then until i can measure no3 at a range of 1-2,most of the time aproc 50 ml a day was fine for me,if you put in too much your glas becomes green and algae grow faster,this is my personal doses and for my tank it did well,start low and look at your animals"

Looking for feedback from folks who may use Calcium Nitrate. If Jawsee uses it, I want to learn more about the stuff. Anyone?

 

[ormet]

I ordered some calcium nitrate - it was 3 bucks for a pound. I tested the water Friday morning getting a value of 0.06 for phosphate. I then mixed up a solution of calcium nitrate and added enough to bring nitrate up to 3ppm. 20 minutes later there was a mini bloom - slightly cloudy water and the skimmer went nuts with thick skimmate. The corals were happy happy during this.

I tested again late friday night, and low and behold - 0.00 on the hanna. Additionally during the day no new cyano, what was there died off, and in the refugia, it literally peeled up off the sand and floated to the surface.

Once I dial in a maintenance dose(if needed) i will just add the nitrate to my vinegar reservoir connected to my dosing pump.

For my 3 bucks i have enough to dose for about 2 years BTW.

This is a bit late, but yes i have experienced this also in the beginning of dosing CaCo3. When bacteria is no longer limited you might get a bacteria bloom.

 

[ormet]

Looking for feedback from folks who may use Calcium Nitrate. If Jawsee uses it, I want to learn more about the stuff. Anyone?

I have used it for a year to keep my Po4 down when needed. Combine it with a good skimmer and a carbon source and it will help you reach your optimal ratio Po4 and No3, whatever that might be. For me, unmeasurable po4 and a hint of no3.

Hello swcc :deadhorse1:

 

[ReefKeeper64]

I have used it for a year to keep my Po4 down when needed. Combine it with a good skimmer and a carbon source and it will help you reach your optimal ratio Po4 and No3, whatever that might be. For me, unmeasurable po4 and a hint of no3.

Hello swcc :deadhorse1:

Ormet, Thanks for the details about your experiences using Calcium Nitrate. I placed an order for a 5 pound bad through amazon late last night. Yes, its super inexpensive and cost me a whole $9 dollars plus another $10 for shipping! I run a bio-pellet reactor and an I-tech 200 skimmer so slow dosing Calcium Nitrate may be is just what I need to color up my pale looking Monti Caps without raising PO4.

Thanks again!

 

[arkuranel]

I will try to explain how to prepare a Calciumnitrate stock solution. Any contribution would be welcome.

Ca(NO3)2.4H20 is Calciumnitrate Tetrahydrate to order from a chemical supplies company.

The molecular wieght of Calciumnitrat Tetrahydrate is 236 grams (Merck). When you dismiss the tetrahydrate (water), the molecular weight of Ca(NO3)2 is 102 grams and 62 grams is NO3 (60 %) and well known: atomic weight of Calcium is 40 grams( 40 %).

When you dissolve 100 grams of Calciumnitrate tetrahydrate in 1 liter RO water you will have 60 grams of NO3 that solution (all in molecular weights).

Also we may easily calculate that for 100 liters of tank, each 0,1 gram of nitrate will increase the NO3 value of water 1 mg/l (simple math: 1mg/l means 1 gram for 1000 liters and 0,1 grams for 100 liters).

Now, to dose 1 gram of NO3 -thus to increase the NO3 contant by 1 mg/l (or 1 ppm) in 100 liters of tank volume you should inject 1,6 ml of that (above given) stock solution.

So you will calculate your dose for your tank volume.

However, once again, I would not suggest such a diverse solution (dosing organic carbon source and calciumnitrate against -tough Luc (Jawsee) did it for some period (around some months) at his TOTM.

If you attempt to do this, I wish you good luck..

 

[disc1]

Your math is off. When you dissolve 100g of calcium nitrate tetrahydrate you have to subtract the water before you do your 60%. So you've got less than 60g of nitrate in this situation.

 

[disc1]

The tetrahydrate is 236g/mol so that is 62/236 = 26% nitrate by weight. If you dissolve 100g of the tetrahydrate in 1 liter of water you will have 26g/L of nitrate in that solution. AUTHOR'S NOTE: oops. Error. See post 180 for the right math.

 

[arkuranel]

Lets check again: The molecular weight of Calciumnitrate Tetrahydrate is 236 grams and out of this 236 grams: 134 grams is water. So we have 102 grams of calciumnitrate. Thus, we have 62 grams of Nitrates ( 60 %) out of 102 grams -rest is water and out of calculation...

However, I would strongly advice to dose not even 1,6 ml/100 liters but perhaps to start with a drop -yes 1 drop- for 100 liters (0,1 ml???) to avoid catastrophy...:

 

[disc1]

Lets check again: The molecular weight of Calciumnitrate Tetrahydrate is 236 grams and out of this 236 grams: 134 grams is water. So we have 102 grams of calciumnitrate. Thus, we have 62 grams of Nitrates ( 60 %) out of 102 grams -rest is water and out of calculation...

However, I would strongly advice to dose not even 1,6 ml/100 liters but perhaps to start with a drop -yes 1 drop- for 100 liters (0,1 ml???) to avoid catastrophy...:

But when you weigh it the water is part of the weight.

The way you are doing it you would weigh out 236g. 102g of that would be calcium nitrate with the balance being water and 60g of that is nitrate. But to do it that way the original weight would be 236g of tetrahydrate and not 100g. You can't ignore the weight of the water.

This is chemistry 101...

 

[disc1]

CRIPES!!! That isn't right either. I was only correcting your math, I didn't notice but your chemistry is wrong too. 4 water don't weigh 134... Water is 18g/mol. 4 waters weigh 72g/mol.

And there are 2 moles of nitrate for every one mole of calcium nitrate. So You've got 72 for the water, 40 for the calcium, and 124 for the nitrate. For a total molecular weight of 236g/mol

So of this 236g/mol of tetrahydrate, only 124g is nitrate. That's 124/236 = 52.5% by weight.

So for 100g of calcium nitrate tetrahydrate you weigh out, you get 52.5g of nitrate.
Along with 17g of calcium, and 30.5g of water.

Dissolving that 100g into 1L of water gets you 52.5ppt (52500ppm) in Nitrate and 17ppt (17000ppm) in calcium.