Fluctuating pH

[BCSreef]

7.8 isn't bad, but it's not optimal. If it bothers you and you've tried several options without success, you could try one of these:

1. Try a reverse lighting schedule if you have a refugium (light the tank during the day and the refugium at night)

2. Run your skimmers air intake line outside, through a window or whatever.

3. Dose some kalkwasser with a dripper or your Auto Top Off. (This will only be a temporary elevation of pH)

4. Or last resort buy a CO2 scrubber and hook to your skimmers air intake. I only say last resort on this because the CO2 scrubber media does cost money. The others are fairly cheap.

I tried 1, 2 1nd 3 (at night) individually and they all pushed the pH up bit. All 3 together really worked well. Keeps pH between about 8.1 and 8.2.

 

[hermitmandy]

Has anyone done a DIY chaeto reactor instead of a typical fuge? I have a spare pump in my tank and have been looking into making one.
The window didn't help for very long. It's right back at 7.8 again, even dipping to 7.3 the other day. D:

 

[Val Shebeko]

Someone mentioned a pump that hd a air hose attachment. This is the one i found

 

[Randy Holmes-Farley Verified Community Expert]

Has anyone done a DIY chaeto reactor instead of a typical fuge? I have a spare pump in my tank and have been looking into making one.
The window didn't help for very long. It's right back at 7.8 again, even dipping to 7.3 the other day. D:

I think pH 7.3 is testing error. Rock and sand would be dissolving.

 

[Myka]

I think pH 7.3 is testing error. Rock and sand would be dissolving.

Yeah, maybe calibration issue. Maybe that 7.3 is 7.5 , and maybe that 7.8 is 8.0. That would be good.

 

[hermitmandy]

I've double checked calibrations with a few different test kits, all check out. It didn't stay 7.3 for long, only a couple hours, before bouncing back to 7.5.

I noticed something interesting recently. My mag had dipped down to 1150, calc to 300, so I dosed aquavitro ions to get the mag back up instead of doing a water change since I had to leave for work. My pH slowly rose from 7.54 to 8.01 over the course of the next few hours, and ORP when from the low 400s (415ish I think it was) to around 375-ish, and stayed that way overnight. By morning we were back at our 7.5 reading again. Dosed the mag again this morning, and lo and behold ORP dropped and pH rose, same as it did yesterday. I haven't tested mag yet today, so I'm not sure what it's currently sitting it.
Any reason it would rise and then drop overnight? Coral-wise in the tank there's 7 mushrooms, around 11 small colonies(<1.5")/frags of zoas, 5 euphyllia, 2 cap montis, 4 birdnest, a milli, and a few acros. The biggest one is one of the mushrooms, who opens about 6-7" wide. I wouldn't think this combo of coral would use so much magnesium, though I could for sure be wrong.