pH... what makes it change?

[chort55]

Ok, so anyone that knows me knows I don't test for anything (very bad don't do this at home ), but I picked up a controller that has a pH probe so since I essentially paid for it I hooked it up.... well I have been somewhat looking at it and have noticed it has changed, typically maybe .05 at most throughout the day (that I have noticed, havent hooked it to comp so I dont have like a full read out of it)..... anyways even these small changes have got me wondering...

What causes Ph to change? Both naturally and through human intervention

 

[islander84]

when the lights come one certain algaes in your DT or sump will intake co2 and release Oxygen causing ph to rise a little...vise versa when lights go out.....thats the main ph swing......now if you setup your refugium light on reverse phototperiod you shouldnt have much of a swing

 

[islander84]

adjusting s.g, alk, and calcium can cause ph swings

 

[islander84]

What kindof controller is it? it should have a data log built in so you can back reference

 

[CJO]

adjusting s.g, alk, and calcium can cause ph swings

Huh?

CJ

 

[CJO]

CO2 is the main cause of pH swings. More CO2 results in a lower pH, less CO2 results in a higher pH.
CO2 can come from many places-

• the fish and coral use oxygen and expel carbon dioxide;
• you do too, which can elevate the CO2 level near the fish tank and lower the pH;
• calcium reactors use CO2 and thus lowers the pH;
• as islander84 said, algae uses CO2 during the day but also expels some at night;

Some ways to raise your pH-

• kalkwasser can react with the CO2 in the water and raise the pH;
• you can also raise the pH by using a CO2 scrubber or by placing the air intake of your skimmer outside of your house

CJ