Alkalinity drop, why and how to bring it back

[balajeek15]

73g redsea, running for 1 and half year. my alk never dropped to 6.0 anytime, see the chart. was dosing before and since my alk kept increasing i stopped the dose for nearly 3 months and Alk was near steady until the recent drop

Two things might have caused, one running chemiclean process in Aug. (don't ask why, many things i tried to bring back close zoas by suggestions here at R2R)
Second I added 10 SPS frags last week.

When I noticed Alk test on Sep 16th as 6.9, I started to dose 2ml every other day for nearly 10 days hoping to bring it back, but looks like thats not enough and today test showed 6.0.

What do you think is causing my Alk to decline and how much dose i can do to bring back around 9?

 

[MnFish1]

First - make sure your test is accurate - double check
second - there are calculators available - to tell you how much to dose based on the tank volume and the drop in alk - over whatever period. Or you can enter your desired alkalinity and yoru current alkalinity and your volume.

Aquarium and Reef Calculators - Bulk Reef Supply

Bulk Reef Supply - Saltwater Aquarium Supplies for Reef Tanks

www.bulkreefsupply.com

 

[balajeek15]

Yes forgot to mention I tested twice with Hanna

 

[jurgenph]

whatever it was that you were fighting disappeared and your corals and/or coraline got happy and started to grow?

J.

 

[balajeek15]

whatever it was that you were fighting disappeared and your corals and/or coraline got happy and started to grow?

J.

No, those zoas never opened.

 

[jurgenph]

No, those zoas never opened.

zoas can be temperamental... but the stonies may like what you did.
something is using your alk.
did your Ca drop too?


J.

 

[melanotaenia]

check you calcium, if that is low, then Alk is being consumed, if your tests are indeed accurate, I would recommend dosing to increase no more than 0.5-0.7 DKH per day until you get to where you want. At 6 DKH you will not lose any corals (most likely), but any lower and you will be in trouble. But make sure to increase Ca, if required, in line with your increase in Alk. It might be a good idea to test your Mg as well.

Forgot to add: 2mL of Alk supplement in a tank your size is going to do next to nothing to raise the Alkalinity; use on of the calculators on BRS, it will help estimate how much to dose.

 

[malacoda]

Yes forgot to mention I tested twice with Hanna

Just because the readings matched, doesn't necessarily mean they were correct.

If something is off with the reagent or the unit's calibration, the second test (or even a 3rd, 4th, 5th, etc.) could produce the same low reading as the first test, even if it's erroneous.

Per the chart above, it looks like your alk has been dropping for the past 4 weeks. Like melanotaenia mentioned, if your Ca has also shown a drop over the past 4 weeks as well, it's a clear indication the alk is being consumed.

Note that it won't be as 'big' of a drop since Ca is consumed significantly 'slower' than alkalinity, but you would still see some type of drop in Ca.

Do you have any LPS or SPS that were already in the tank prior to the 10 frags you added last week? Some corals can take weeks or even months to completely acclimate and kick into full-out growth mode.

If you haven't seen any drop whatsoever in Ca, there's a good chance something with the Hanna checker is off. Get another test kit/checker and retest your alk with that.

 

[balajeek15]

zoas can be temperamental... but the stonies may like what you did.
something is using your alk.
did your Ca drop too?


J.

Every weekend i check all the parameters, since i was out last weekend and did not test it. last night when i came back from work i noticed the bird nest is fully white (just that one, other one seem fine), I do remember 2 days ago seeing it will full of polyps. So I tested No3 (5) ,Po4 (0) and KH(6.0) and was surprised Po4 is zero and KH is 6.0.

I did not test Ca, may be i should've done that, Ca never dropped below 500 for me for a very long time. In the two part Bionic I had used most 50% more Alk than Ca.

 

[balajeek15]

check you calcium, if that is low, then Alk is being consumed, if your tests are indeed accurate, I would recommend dosing to increase no more than 0.5-0.7 DKH per day until you get to where you want. At 6 DKH you will not lose any corals (most likely), but any lower and you will be in trouble. But make sure to increase Ca, if required, in line with your increase in Alk. It might be a good idea to test your Mg as well.

Forgot to add: 2mL of Alk supplement in a tank your size is going to do next to nothing to raise the Alkalinity; use on of the calculators on BRS, it will help estimate how much to dose.

Yes i should've check Ca too but didn't, will do when i get home. (I wish i had Trident to keep constant monitor, still waiting list) . BRS calculator tells me to required dose is 360ml but it does not tell me how much to dose in what period.

 

[balajeek15]

Just because the readings matched, doesn't necessarily mean they were correct.

If something is off with the reagent or the unit's calibration, the second test (or even a 3rd, 4th, 5th, etc.) could produce the same low reading as the first test, even if it's erroneous.

Per the chart above, it looks like your alk has been dropping for the past 4 weeks. Like melanotaenia mentioned, if your Ca has also shown a drop over the past 4 weeks as well, it's a clear indication the alk is being consumed.

Note that it won't be as 'big' of a drop since Ca is consumed significantly 'slower' than alkalinity, but you would still see some type of drop in Ca.

Do you have any LPS or SPS that were already in the tank prior to the 10 frags you added last week? Some corals can take weeks or even months to completely acclimate and kick into full-out growth mode.

If you haven't seen any drop whatsoever in Ca, there's a good chance something with the Hanna checker is off. Get another test kit/checker and retest your alk with that.

My Ca test for a very long time is 500+ (I always finish the 1ml drops to end to get the blue color on RedSea) many times i wonder if its even accurate, same with Mg, its 1600+ with RedSea again. I don't know if i can trust the test anymore, the last time i did triton ICP it came up with Mg being a bit low, but at the same time my RedSea test came with 1600+

I will check Ca tonight to see if its consumed.

Yes I had LPS and soft corals for a while and some 4 SPS frags back in mid Aug

Since you mentioned about Hanna checker, I thing i noticed when testing last night is when i Add C1 and press, it took like 10 sec to say 'Add C2' . usually its 2-3 sec. (this hanna is purchased Oct 2018 from ebay as new)

 

[leepink23]

My alk would drop with the Hannah checker when the reagents got a few months old, caused me to over dose alkalinity a few times

 

[balajeek15]

My alk would drop with the Hannah checker when the reagents got a few months old, caused me to over dose alkalinity a few times

Really, the reagent i used was the last few ml left in the bottle, so that could be an issue?
Not sure about the expiration, but i got it Oct 2018. Anyway I recently got the reagent form BRS becaz i know its finishing up, I will check with new reagent tonight, if thats different that we know who the culprit is. dang!

 

[shred5]

Yes forgot to mention I tested twice with Hanna

Yea I agree I would check with another kit or take a sample to lfs..
I have had bad kits and kits go bad after a while. I always keep several kits on hand and if I see something weird I double check to verify...

Alk can be raised by using one of the additives. I would bring it up slowly.

Even without allot of coral their are other things in a reef that consume alkalinity like some algae and bacteria.

 

[balajeek15]

I tried opening new bottle of reagent and it still showed 6.0, started to increase the alk dose to 15ml every two hours and as of today (Sat) afternoon it shows 7.5 alk. Now reduced the dose to 10ml and hoping to increase a bit slowly.

Also check Ca and it is around 450 (RedSea) which is a decrease from 500+, i am not dosing Ca now and want to see if Ca still comes down to 400 or something and then i would believe the test kit is indeed showing some variance, if it does i will then start Ca dose too.