Help my pH is too low!

[bbales]

Ok, so i have had my 34g RSM for 2+ years now and it has been the most stable tank ever. However over the past few days the pH has been as low as 7.9 (in the morning right as lights come on). Every other water parameter is perfect and I have been doing 5 gallon water changes every day and by the end of the day the pH is back down. The only thing that id different at all is I fed my Harlequins a formia starfish instead of a choc chip or sandsifter, I thought maybe it had fowled the water but nitrates, nitries, and ammonia are all zero. My scolymia and anemone loof fine but zoas, frogspawn hammer brain, toadstool, gorgonian and even GSP are all closed up =/

 

I am really worried about it and I have not clue what is going on chemically that wont allow my pH to stay up.

 

Any help would be greatly appreciated!

 

THANKS!

[Neya]

This is normal and probably not causing the irritation to your corals.

Ph will always be lowest right before and after lights go on due to co2 buildup and lack oh nightly photosynthesis.

My morning ph has more than a few times been lower than 7.8 with no I'll effects.

 

Keeping ph stable at night can be accomplished with a sump/refugium with chaeto (or other macro) a nightly photoperiod.

I'm not well versed in calcium reactors but I think that too could be an option ??

[reefer916]

Ok, so i have had my 34g RSM for 2+ years now and it has been the most stable tank ever. However over the past few days the pH has been as low as 7.9 (in the morning right as lights come on). Every other water parameter is perfect and I have been doing 5 gallon water changes every day and by the end of the day the pH is back down. The only thing that id different at all is I fed my Harlequins a formia starfish instead of a choc chip or sandsifter, I thought maybe it had fowled the water but nitrates, nitries, and ammonia are all zero. My scolymia and anemone loof fine but zoas, frogspawn hammer brain, toadstool, gorgonian and even GSP are all closed up =/

 

I am really worried about it and I have not clue what is going on chemically that wont allow my pH to stay up.

 

Any help would be greatly appreciated!

 

THANKS!

 

How's your alk?

[MikeTR]

What are your alk and calc readings? If you live in an apartment.. crack a window. Excess CO2 in the home DOES lower pH. Believe it. pH also drops at night because CO2 levels rise due to the reduction in photosynthesis.. 7.9 is not low. 7.6 is low. A swing from 7.9-8.1 is perfectly fine. Stop changing the water and stop chasing the pH. You're effecting the overall stability of the tank and your pH will stabilize over time. Work on maintaining alk and calc where they need to be. 9-11, 400-460

[MikeTR]

To get a bit more technical.. pH is lowered by an increase in carbonic acid, the mixture of CO2 and water. The introduction of the acid lowers the pH. We know that on the pH scale lower numbers are acidic.. alkalines are higher. So by introducing a buffer, bicarbonate, you'll bind with some of these CO2 molecules and increase pH, temporarily that is, until that CO2 is again replaced by the respiring organisms in the tank. Also the addition of bicarbonate increases alkalinty (dKH). So if you keep adding buffer, and only temporarily bind the CO2, you still end up with low pH and a jacked dKH.

[bbales]

What are your alk and calc readings? If you live in an apartment.. crack a window. Excess CO2 in the home DOES lower pH. Believe it. pH also drops at night because CO2 levels rise due to the reduction in photosynthesis.. 7.9 is not low. 7.6 is low. A swing from 7.9-8.1 is perfectly fine. Stop changing the water and stop chasing the pH. You're effecting the overall stability of the tank and your pH will stabilize over time. Work on maintaining alk and calc where they need to be. 9-11, 400-460

 

Thanks for the advice, but wouldnt the AC be bringing O2? And my other tanks are looking fine even the smaller 30g. My calc is 400, and my alk is 10, this is after I dosed just the alk part of the buffer system in an attempt to get my pH higher, which is now 8.2. So I guess I will just keep checking. Opening a window isn't really an option, its 85 degrees out here. The salinity is 1025, the temp is 79.

[MikeTR]

I live in fort myers.. i feel your pain .. The A/C only recycles the inside air... and you only need to crack the window for 30 mins to an hour. I thought the same about excess CO2 in the house until I go on vacation and I come back to a higher pH reading.

[scalowag]

I'm still learning but what miketr and neya said is correct.

 

in my experience the pH doesnt affect the corals at least not in the short term but it will certainly stress the fish in your tank.

 

in addition to dosing what i do is put in an air-stone at nights and that has helped.

[bbales]

maybe i should be considering maybe pH is not what is wrong, but I have no clue thats the only thing I can see as a potential. I am really worried tho. this tank was my first and all the corals are so nicely grown in. This tank also has a protein skimmer and very often when it gets too low it blows bubbles, I made it blow bubbles intentionally to see if that would help. If things dont progress in the right direction I might switch some of the corals over to one of my other tanks

[MikeTR]

So your question really is.. why are all my corals closed up?

 

How many days in a row have you been doing the water changes? Change in lighting or bulb?

[lakshwadeep]

This is a very good guide to pH; click on the section "why does pH fall" to learn about the multiple factors that contribute to "low pH".

http://reefkeeping.com/issues/2007-05/rhf/index.php

[bbales]

thankyou guys, and I did 2, 5 gallon water changes 2 days in a row, I just took out the hammer and brain and toadstool, those were the worst off (well the toadstool is fine, just closed). so hopefully those pull through.