Have some question about PH.

[InDahOcean]

So my PH seems to fluctuate....I don't think that is a normal thing. Like usually in the morning the PH is around 7.5-7.8, and in the evening it is like 8.0-8.2. I don't know if that is a normal thing, or is it a bad thing. Any suggestions?

 

[Sabellafella]

So my PH seems to fluctuate....I don't think that is a normal thing. Like usually in the morning the PH is around 7.5-7.8, and in the evening it is like 8.0-8.2. I don't know if that is a normal thing, or is it a bad thing. Any suggestions?

Diurnal ph swings happen in all reef tanks, give it a quick search can give you some detail of why it all happens. Absolutely normal, just the 7.5 reading isnt likely. Using a test kit i assume?

 

[InDahOcean]

Diurnal ph swings happen in all reef tanks, give it a quick search can give you some detail of why it all happens. Absolutely normal, just the 7.5 reading isnt likely. Using a test kit i assume?

I have an Apex with a PH probe. The 7.5 was only one time that I saw it. Ok that's a good new. Does leaving the light on longer make the PH stable? Or what do you suggest?

 

[michellem]

You should test around the same hour better at night.

 

[Sabellafella]

I have an Apex with a PH probe. The 7.5 was only one time that I saw it. Ok that's a good new. Does leaving the light on longer make the PH stable? Or what do you suggest?

Technically yea, but its not going to make it stable, stuff like a refugium growing macro at night, dosing kalk or the alk portion at night will all thin out the swing. You can raise ph with a simple airstone, outside skimmer line, even a window open in your home.. as long as your alks in the right range

 

[jeremy.gosnell]

During the day, the algae within coral tissue (zooxanthellae) along with algae within the tank are photosynthesizing, so they are assimilating co2 and releasing o2. This drop in co2 causes ph to rise and stabilize with a higher hydrogen reading, thus higher ph. At night, when that photosynthesis stops, co2 begins to build up and ph drops. CO2 has an acidic effect on water, thus lowering ph. There are two options to buffer that and minimize these fluctuations. One, a large refugium (about 25% the water volume of your tank) filled with macroalgae that is reverse lit (meaning the light kicks on at night, when your tank lights go out, and kicks off when your tank lights come on). Then, the photosynthesizing algae can absorb some of the excess co2. Two, adding a co2 reactor to your protein skimmer. These use medical grade co2 absorber to pull co2 from the air entering the skimmer, thus helping to dilute co2 in the tank water. This may be an issue with carbonate/calcium absorption by the corals within your tank. Are you dosing and if so, what are you using. Likely a more effective way to minimize these swings and buffer ph would be the addition of a kalkwasser reactor.