PH swings. How much is to much?

[johnsonpics]

Hey Everyone,

I'd love some peoples opinions on this. Here's my situation. I have a 34gal All in One Cube w/ skimmer. I've been using Kalkwasser in my ATO for about a year now with absolutely great success with SPS growing like crazy. Also, I recently got an APEX and a Hannah Alk checker. So I've been able to monitor PH and Alk more closely to keep track of everything. Everything sounds great, the tank looks great, corals are growing, etc. No real problem.

So here's where the question comes in. My Ph and Alk swings are crazy. On paper and in theory, they are way to big of swings to be healthy for the tank. Ph range is 7.8-8.4 daily, and Alk is about 7-11 daily, both spiking when the ATO kicks on.

Thanks in advance for any and all comments!
Chris

 

[bonomo53]

What test kits are you using? The ph swing is ok mine goes from 7.6-8 daily with no issues but that alk swing can't be right if your tank looks great. A swing like that would cause all sps to rtn and most other corals to die i would double check with another test kit.

 

[reefiness]

I agree with bonomo, I have a similarly large ph swing according tot he apex from 8-8.4.

An actually alk variation like that seems high to me as well. Is it possible you were sampling water that was close to your input source of alk? For example, if using a doser in sump, did you happen to take a sample of water from the same compartment or one downstream as the alk was being dosed or shortly after? Thats really the only way I can see you getting such a swing.

 

[johnsonpics]

Hey Guys,
I'm using a Hannah digital checker and a Red Sea kit for Alk. Also, I always let things settle for 10 min or so before testing after the ATO turns off. These are all reasons why I am perplexed as to how everything is looking great, but the numbers are a touch scary.

I dunno?

 

[reefiness]

Hey Guys,
I'm using a Hannah digital checker and a Red Sea kit for Alk. Also, I always let things settle for 10 min or so before testing after the ATO turns off. These are all reasons why I am perplexed as to how everything is looking great, but the numbers are a touch scary.

I dunno?

I assume you are using kalkwasser in your ATO water? 10 minutes may not be enough time to be sure the water is 100% mixed. If you can figure out approximately how frequently your ATO adds water to your tank and try to aim at taking a measurement shortly before the ATO triggers it may be better. Or if you unplug your ATO and wait about an hour or 2 before taking a sample of water.

 

[theMeat]

Ph and alk work hand in hand. Meaning, usually, one goes up or down, so does the other

You can't have the ato tube pulling water from the bottom inch or two of the saturated with kalk water reservoir

Would say try to figure a way to make the top off chamber smaller so the ato gives smaller amounts more often, or run your fuge light at night to stabilize ph. But with an all in one system you don't have those options.

If everything is good, don't worry about it