Calcium and Alk Consumption problem is driving me nuts, please help!

[greg683x]

Ok so on my reef tank I have 12 or so frags of sps that have started to take off a bit.

for a long while I was dosing Alk for about 1dkh of consumption a day about about 8 or so ppm of calcium a day.

several weeks ago after adding a couple new frags and after seeing good growth I noticed my Alk was dropping and I needed to dose more. When trying to figure out my new dosage amount, the amount I was seeing I was gonna have to dose was getting way too high. Getting to be over 2dkh a day, almost 300ml of sodium bicarbonate solution in a day, plus kalk being mixed in my ATO.

After doing some reading and making a post or two I thought precipitation might be an issue so I decided to stop dosing for a a couple days but still leave kalk mixed in my ATO, my Alk slowly dropped down to 7 and my calcium down to about 400-410ish. it kinda held there for a day, then dipped down to 6.7dkh and 390ppm. So that night I decided to dose for one dkh and bring it up to 7.7, and dose the same amount for calcium to keep it balanced. I separated the calcium and alk dose by 20 minutes to give it time to mix. When I restested my Alk, it had not budged, still at 6.7. Its almost like when I added the calcium after the alk, it canceled out the Alk I dosed, because when I then added again the same amount for Alk, I saw the jump I was looking for up to 7.7. Im sure though its safe to assume that 2nd dose of Alk brought my calcium level down.

Fast forward to tonight (which is the following night) and the same thing happens again.

Whats going on and what am I doing wrong here? I know calcium drops alk, and alk drops calcium, but that fast?? and canceling out an entire dose? if its this severe wouldnt our dosing during the day with dosers just cancel each other out?? Theres something fundamental here that Im missing obviously but I just dont know how I could have the dosing down pat a month ago keeping Alk at 8.5ish and calcium around 430-440 and have everything get turned upside down by this. Any help would be greatly appreciated


....also would elevated Mag have anything to do with this? I wouldnt think so but it would be worth mentioning. I usually keep my mag at 1400, but a couple weeks ago I had a faulty test reading and added some mag solution that I should have and its sitting at just over 1500 right now.

 

[Ou8me2]

I'm not sure if this applies to you but an interesting video by BRS.

"I add more and more Ca/Alk and the levels won’t rise?"

https://www.youtube.com/watch?v=hSg3KGTuRCo

Basically, if you overdose or are dosing too much of each it will cancel out each other.

 

[greg683x]

I did see that video and that's what prompted me to stop dosing two part and let my levels bottom out over a couple days. The problem is still persisting though, even at small one times doses of 50ml of sodium bicarbonate and calcium 20min apart

 

[mattgumaer]

This does not make much sense, particularly with the high Mag. I would suspect one of two things is going on: 1) one or more test kits is giving bad readings; or 2) if you're manually dosing, when you're dosing, you're getting localized levels of calc and alk high enough to cause precipitation.

On test kits, the other day I ran three alk tests: 1) Hanna with older reagent (8.3); 2) Hanna with new reagent (7.2); and 3) older Salifert that was lying around (7.7). Given the wide range, I took some water to the LFS to have them test it. It came back a 'little over 7'. The lesson was the newest test reagent gave an accurate result. So, if you're getting readings that don't make sense, consider the age of your test kits. If you're like me, you test alk the most, followed by calc, followed by mag.

With respect to dosing, I don't know if you're using dosing pumps or doing it manually. If you're doing it manually, with that much, you'll want to do it very slowly in a high flow area. If you don't use dosing pumps, it may be time to think about getting a couple for calc and alk. You don't say what size your tank is but 300 ml of alk seems crazy high, particularly when adding kalk as well.

Ultimately, I think it has to be bad tests and/or precipitation.

Matt

 

[Browndawg80]

What size tank is this? 300 ml a day plus kalk is a ton of 2 part. Sounds to me like you are grossly overdosing the tank and the solutions are precipitating out. My advice would be to do as large a WC as possible ( at least 50%) and flush all of that polluted water out of there and start fresh. Start dosing the 2 part at a much smaller rate say 15-20 ml a day and let your doses run for a week at that amount before retesting. Worry about long term trends with your alk and cal levels instead of testing every day and chasing numbers.

 

[greg683x]

My tank is 90 gallons, id put the total tank volume at 100 gallons.

I have the BRS 1.1ml dosers for calcium and alk. Before the levels started acting up I was dosing about 142ml a day, which covers about 1 dkh of consumption. I always thought it was a bit high but never thought too much of it bc I never had problems keeping my levels locked in.

Somethings happened over the past few weeks, the new corals I added started to take off, I began to see a drop and ALK and tried adjusting accordingly.

I do have evidence of precipitation in my sump bubble trap and in my return pump chamber, which past where the dosing is done.

if im continuing to dose here is the calcified residue on the glass of the sump possibly causing this? Ive tried dropping the dosing levels down, to 50ml at least and I get the same result. Is the water just contaminated at this point?

 

[outssider]

kalk will increase the ph where it's being dumped in. increased ph will increase the chances of precipitation. This, combined with your dosing may be what's causing the precipitation.

 

[greg683x]

so i think the problem is definitely precipitation.

When I got home from work today I tested Alk and it was at 6.9-7ish. i decided to try and bump it up and keep it around 7.7 According the calculator on BRS that called for 100ml of sodium bicarbonate solution

today though I decided to dose into the main display tank right into a powerhead. im gonna dose the same amount of calcium as well (with an appropriate amount of time between to keep the chemicals balanced. so first I dosed 100ml of calcium chloride solution, i looked into the display and noticed a small amount of stuff floating around. I waited just over 30 minutes and dosed 100ml of sodium bicarbonate solution. I looked into my display again and it looked like sand was floating all over the place, so the solution appears to be clearly precipitating.

it all settled and I checked my Alk again, and it was at 7.3. Half of the rise the dose was supposed to supply.


So what needs to be done here?? The levels are already so low, Im dosing equal amounts of calc and alk but its still doing this. Is the water just contaminated at this point and I need to do a MASSIVE water change and try to start over with tiny amounts like BrownDawg said?

 

[greg683x]

kalk will increase the ph where it's being dumped in. increased ph will increase the chances of precipitation. This, combined with your dosing may be what's causing the precipitation.

the PH is 8.1-8.2 and its been that way even when the system was stable. Even if this was the case, you would think the precipitation would stop when i let the levels drop down to the bare minimum

 

[Browndawg80]

The calcified residue in and of itself isn't the problem rather its showing you that you're having a problem. A little build up on the side of the glass or wherever the 2 part drips in is normal but heavy buildup is a sign of precipitation.

Is there any way you can post a picture of the tank just so we can see how many corals you have and how big they are? I'll try to post a pic of my tank later but it's a 150 gallon with 75+ corals and I'm only dosing 150 ml a day alk and 170 calcium if that helps for reference.

BTW why are you using both kalk and 2 part? I've never used kalk but my understanding is that it can cause PH problems sometimes. I would do the aforementioned WC and dump the kalk for now just to keep it simple until you figure out exactly what's going on.

 

[greg683x]

im attaching some pics of my tank. theyre not the greatest especially since the blues are on right now but itll give you an idea of what I got.

I do dose Kalk, for what its worth, there havent really been any ph swings, its been steady at 8.1-8.2 - Im desperate to get to the root of this problem though so when I refill my ATO I'll just use regular RODI. the fact that youre only dosing that much with that many corals and im dosing nearly the same amount shows a lot here

i just dont understand why I'm continuing to have the problem even though ive backed way off on the dosage amount

 

[Browndawg80]

I can't explain to you why it happens but it's almost like you cross an invisible line where you go from dosing the tank and seeing the levels rise as your dosage increases accordingly to a place where all of a sudden you're overdosing the tank. Something happens and your water gets fouled up and bonded on a molecular level.

Either way I would do as large a WC as possible or 2 or 3 decent sized ones back to back to flush all that old water out of there and start fresh. Based on the pics you provided if I had to guess your tank will end up between 20-40 ml a day for now until your corals start growing. Others may disagree but I think those BRS calculators are confusing and mess people up trying to figure out daily consumption. I would do the water changes and then test the levels and record the results, then I would set my dosage at a small amount like 10-15 ml daily and let the doser run for 7 days and retest. At that point you should see your levels slightly rise and then readjust your doser as needed.

Example: you do the WCs and test and you're at 7.5 and 400 to start. You then set the doser to 15 ml each daily and let it run for a week before you retest and then you're at 8.5 and 410. At this point if you're shooting for say 9.5 and 420 you would raise the dosages another 10 ml each bringing you to 25ml each daily.if it runs for another week and you retest and find yourself at your target levels then leave it be at 25ml daily. If however you're at 11 and 470 then you'd back the doser down to 20 ml each daily.

Hope this helps, good luck!

 

[Browndawg80]

Also are you dosing into a high flow area? If you see the alk solution hit the water and slowly sink then that's a problem. It should dissolve within 1 or 2 seconds after hitting the surface of the water.

 

[tkeracer619]

I've fought this several times. Most recently in my 34gal coral qt.

I stopped fighting it and installed a calcium reactor. A masterflex setup. 2 days of adjustent and haven't touched it in 2 months.

 

[Browndawg80]

you have to right click to see my tank but for reference sake im at 151 and 171 daily of ESV Bionic. Those dosages keep me at 9.0 and 400. My preferred range would be 10.5 and 400 but the ESV gets expensive so I haven't raised my dosages but if I wanted to bump it up to get there I would raise to 170 and 190.

 

[mattgumaer]

If you have a local fish store or someone else that can double check the test results, I would try that. It just doesn't make sense to me that you would get that much precipitation with relatively high mag and relatively low alk. I'm guessing your mag is actually lower or your alk is actually higher than you think.

Matt

 

[greg683x]

so yesterday I did a 35% water change on the tank and I also emptied the ATO of a kalk saturated solution and just put regular RODI water in.

Tested the water about an hour after the water change and the water was 7.7dkh 430 calcium and about 1400 magnesium

checked the water today about 22hours later and we've dropped to just under 6.9dkh presumably making it to close to 6.7 by the time we actually hit the 24hour mark.

is there any other reason at this point but to assume my tank is actually consuming this amount? The only thing of note is that just consumption rate didnt change after removing the kalk, which we can assume was just precipitating or causing the precipitation?

Im gonna test for a couple days to see if the consumption rate stays the same but at this point I doubt that it will change, which would leave me dosing about 142ml a day to maintain the 1dkh drop. The only thing bugging me is if I start to dose at a 1:1 ratio my calcium is gonna go through the roof fast. Just still seems like a whole lot

 

[hkgar]

I might have missed it, if reported, but what is your Mag level? It needs to be at least 1250.

 

[greg683x]

it was at just over 1500 before the large water change, now its around 1400.

if I switch to soda ash instead of bicarbonate it lowers my dosage by 50% which would let me dose at a more 1:1 ratio

I think 70ml is still a lot for tank but its easier to understand than nearly 150ml bc you have at a 1:1 ratio.

 

[zsuman101]

it is possible to strip alkalinity using kalk to fast, ie say you dose your 2 part and then your ato kicks on dumping saturated kalkwasser carbonates could be bindind and dropping out of solution causing ca and alk stripping. for me, i rarely use more than 1 tsp/gal in my kalk otherwise my alk goes sky high. i mix my kalk let it sit overnight then siphon off the water above what is settled. with this i get the advantage of increased ph without the worries of sky high alk or worse alk and ca stripping. good luck zsu