Alkalinity issues

dannyab84 · Apr 5, 2019

Hey guys, so I’m battling a alkalinity issue which I don’t seem to be understanding correctly. My current test is:

Mag: 1350
Cal: 400ish
Alk: 3.5

I just dozed 100 ml of bicarbonate to the system (75 gallon, 20 gallon frag 20 gallon sump)
Estimated water amount around 90 gallons.

I am trying to just raise my alk 1.0 a day, but when I am dozing the test kit shows the alk falls.

I was at a 0 after I put in the 100 ml.

I have a very heavily stocked tank with mostly zoas. I’m very confused on to what’s going on.

I’ve dozed both soda ash and bicarbonate I. The last month trying to get it to raise.

Maybe it is the test kit? Everything In my tank looks happy.

Also does bicarbonate precipitate?

I know soda ash does. Which I know to add slowly.

Thanks for any help guys. I will really appreciate it.

KrisReef · Apr 5, 2019

What about the test kit?
What product are you dosing (soda ash?)
Are you adding other products at the same time?
This is a mystery!

I think you should be adding baking soda (bicarbonate)

Mastiffsrule · Apr 5, 2019

Is that 3.5 alk meq/l which would be Dkh which is 9.8.

dannyab84 · Apr 5, 2019

I’m using bicarbonate right now to raise right now.

Test kit is salifert might go buy a Red Sea today or tomorrow.

And the 3.5 is DKH

BeejReef · Apr 5, 2019

3.5 dkh is crazy, crazy low. Even though zoas are hardy, I suspect even they'd be dead or dying if your tank was, in fact, that acidic. I'd, personally, stop dosing anything until you're able to get a second test kit to confirm. Something is not right

rushbattle · Apr 5, 2019

dannyab84 said:
I’m using bicarbonate right now to raise right now.

Test kit is salifert might go buy a Red Sea today or tomorrow.

And the 3.5 is DKH

Please please double check with another kit. I think this is testing error.

dannyab84 · Apr 5, 2019

Yeah I think so too. I have huge SPS Colonies which are very happy with all their feeders out.

dannyab84 · Apr 7, 2019

So it is not the test kit. Both kits test low around a 2 right now. And my upstairs tank is right at a 8 dkh.

I dozed 200 ml of bicarbonate last night with no raise. Is my tank using that much alk?? It should have raised the tank 1.5 dkh.

What should I do. A massive water change? This is driving me crazy.

rushbattle · Apr 7, 2019

dannyab84 said:
So it is not the test kit. Both kits test low around a 2 right now. And my upstairs tank is right at a 8 dkh.

I dozed 200 ml of bicarbonate last night with no raise. Is my tank using that much alk?? It should have raised the tank 1.5 dkh.

What should I do. A massive water change? This is driving me crazy.

Water changes almost never hurt, so that’s a good plan.

But here’s the thing, it’s actually pretty hard to get alkalinity that low without adding acid to the tank. No way a calcifying organism can get it that low, should stop around 6 or so dkh if I remember correctly. Can you test newly mixed water to see what you get?

If water changes don’t resolve the issue then I’m not sure how to proceed. It still seems like error to me. How are you measuring salinity?

OutsideBrian · Apr 7, 2019

What is the ph of your tank?

Mjrenz · Apr 7, 2019

I read through this I didn't notice any mention of ph

Mjrenz · Apr 7, 2019

OutsideBrian said:
What is the ph of your tank?

You beat me to it

Mjl714 · Apr 7, 2019

If your sps looks good/happy, whatever you do, do it slowly. I would do small water changes as you continue to try and determine what is happening.

Auquanut · Apr 7, 2019

Just trying to wrap my brain around this. Wouldn't alkalinity that low be immediately deadly to fish and coral? How long has this been going on?

dannyab84 · Apr 7, 2019

I have no idea what the PH of my tank is. I don’t really know how to test that.

I just bought an aqua Forrest alkalinity test kit yesterday. It comes with a sample vial containing what should be 7.3 dkh. It tested low at around a 6.3..

I cross checked it with the salifert and it checked at a 0...

So the +/- 1% would test a 6.3.. it is on the lowest end, but kinda correct I think.

I’m so confused..

Should I just take a sample to my LFS before doing the water change? How much of a water change should I do? I have about 50 gallons of freshly made salt water which is testing low too at 6ish dkh.

What a head ache