Raising pH

Surfside74 · Jun 17, 2014

My ph in my tank runs kind of low. Let me first start of by saying everything in the tank looks great. During the day, the ph will rise up to 7.9 and change. During the night, it will fall to around 7.75. All other levels are good and I dose/drip alk at night after the lights go off. I cannot open doors or windows to raise it up because I live in Florida and it is hot and humid. Any other ideas. I know not to chase numbers but mostly curious I guess to see if there are any solutions I could employ. Thanks.

tigerdragon · Jun 17, 2014

Do you have a fan blowing on tank surface? Also how much air does your skimmer bring in? A skimmer that brings in a lot of air will help bring ph up have noticed that on my 90 when seeding bio pellets if i shut down skimmer will drop to 8.19 after bringing skimmer back up came back up to 8.23 it injects a lot of air. If temp at night isnt too bad open at night may help or else you will have to buffer

zemuss · Jun 17, 2014

This is a common issue in florida and it is a CO2 buildup in the house issue. Best thing to do is open the windows up on days where you can turn off the ac for a few minutes. If there is a breeze open up one side of the house and the other side to get the air flowing. Honestly, this is the cheapest and easiest way for you to solve the issue. You can do it without raising the temp of the house too by only opening some windows, for instance the ones around the tank.

I have done the CO2 scrubber thing and if you have an excess of CO2 in the air it will deplete the Co2 scrubbing material fast.

Surfside74 · Jun 17, 2014

OK. Thanks. I guess overall there's no reason to really worry if everything is happy. The skimmer is in the sump inside of the stand obviously. Could I run airline to extend the skimmer tube outside of the stand? Would that help? No fan running. My tank stays right at 78 debts add it is. Don't want to drop temp.

tigerdragon · Jun 17, 2014

is sump area of stand open? open a door on the stand leave open and see if that helps what is your kh?

beaslbob · Jun 17, 2014

As stated by others it is co2 that is lowering you pH.

I think you will find that if you add macro algaes (usually in a refugium) or an algae turf scrubber, the ph will rise to 8.4-8.8 just before lights out with the api test kit.

When I had lower kh, ph would drop back down at night to around 7.9. But after adding baking soda to keep the kh up, the nightly drop was much less and still above 8.2 or so at night.

What happens IMHO is the tank becomes a net consumer of carbon dioxide and producer of oxygen each 24 hour period.

my .02

zemuss · Jun 17, 2014

If you run a ATS or Algae and have the lights on a reverse schedule then the ph might not swing as much..

foxhuntr · Jun 19, 2014

just get yourself an airpump and a couple of airstones and put the airstones in you sump and pump in fresh air from outside with the pump....I have been doing this for years and I works great......I run my airhose thru a little hole to the outside and caulk around it and put my airpump outside and set a planter on top of it incase it rains

prsnlty · Jun 19, 2014

I fixed my ph problem by running a 1/4" airline tubing from the skimmer air intake to the outside. I drilled a hole in my outside wall like running cable and used a cable plate over it. My ph is at 8.0 at night and averages 8.4 durning the day. The exact info is in my 180g tank thread. Page 6 I believe.

Surfside74 · Jun 20, 2014

Seems I may have fixed the problem. I re calibrated the probe again but took longer doing it. My ph this morning was 7.84. It seems to have been a probe issue after all. I will monitor it and see what happens. Thanks for all the information though.