Low PH problems / solution

[hammondegge]

I know many have posted lately about ph worries. Many with just slightly lower than comfortable levels. Mine has been dropping to 7.85 everynight and i tried everything i could think of to stop it from going so low. Reverse photo-period, adjusting 2-part, dosing kalk in top-off and supplemental etc. despite all my efforts the PH would return to 7.85 by morning. we have a 1000sq ft house 2 adults and 2 dogs. it has been closed tight for months because of the heat so i am sure the CO2 is the house is higher than normal. knowing that high dissolved CO2 concentrations can cause this trouble i attempted to draw air from outside of my house to supply the skimmer. that didnt work either. i kinda gave up.

a couple of days ago i found an air pump and air stone in a storage box so i set it up to run in the sump. the next morning the PH had dropped to only 7.95 and has risen to 8.22 during the day. the air stone was the only change and the result was almost immediate.

FWIW i thought i would share this.

[fishypets]

Robert,

My p.h. sometime will drop below 7.6 at night. What is your KH?

[hammondegge]

10-11 dkh

[fishypets]

Then I wouldn't worry about it.

[ejaustin]

But what makes the pH go down? (Down means the water is becoming more acidic, right?) I understand the idea that photoactive critters like algae consume CO2 and since CO2 is acidic, when the lights are on the pH tends to go up. And that that is the rationale for using a reverse photo-period for an algae refugium to dampen the swing in the pH over a 24-hour period. But what else in the tank is acidic? Ammonia? Nitrites? Nitrates?

And what is basic (in the sense of being a base, as opposed to being an acid)? Aragonite? Can't think of anything else at the moment?

What about most foods? How do they tend to affect pH?

Maybe I need to start my own "Silly Newbie Questions" thread.

ej

[hammondegge]

ej - that is a text book worth of stuff. i think you are spot on with what you mentioned though. i would like to understand more of the contributing factors too. i have found plenty of articles on alk and calcium with ph a secondary concern, not so much on the many reasons that ph moves around. alkalinity is essentially a measure of waters ability to buffer ph, right? and the right balance should be maintained between alk and calc. so maybe that is why the emphasis is not on ph.