Can't get pH up no matter what I try... PLEASE HELP!!!

CWH · Feb 16, 2023

I need some help.

I have a 2.5 month old Red Sea Reefer - total water column is 112g. Have a bunch of coral that mix of SPS and soft (all looking good). I had ich in the tank about a month ago that killed everyone but a chromis and am waiting it out for the full 70+ days before putting other fish back in.

In my sump, I have bioblocks and skimmer in 2nd chamber, ton of sea lettuce in 3rd chamber. I added a CO2 scrubber to the skimmer that was working amazing until the pellets were used up, I changed them but have never been able to get the pH back up consistently ever since

Current water parameters are:
pH: 7.93
ORP: 238
Salinity: 1.027 (I know that's on the high side, I have a water change coming up)
Alk: 12 or more since I keep trying to add buffer in there to raise the pH
Ammonia: 0.25 - I stopped measuring this after all the fish died from ich. So I am not sure why it peaked up. I feed the chromis and coral every few days so ????
Ca: between 300 and 360 (i supplement regularly)
Magnesium: between 1240 and 1340 (I supplement regularly)
Nitrate, ite and Phos all zero

I tried adding ozone a few days ago thinking that maybe there was too much biomaterial - tank is clear but no change.

I will add buffer to the tank - the pH will jump about 0.2-0.3 then it will come right back to >8 in a matter of an hour or so. I'll add kalk...same thing.

I'm still figuring a lot of this out as I go so I apologize if this is beginner level stuff that I'm not getting

Help!

TheDuude · Feb 16, 2023

No need to chase PH 7.9 is perfectly acceptable and will grow corals just fine

Graemesreef · Feb 16, 2023

I think getting your calcium up will help stabilize your alkalinity which in return will help your ph stay stable with the scrubber running. I would start there.

Dburr1014 · Feb 16, 2023

Alk @ 12, yikes

14 foot reef · Feb 16, 2023

What "Buffer" are you using? this might be your issue.
Also have you ever measured the CO2 in your home. If you have High co2 in your home, no matter what you add to raise PH, you will probably never beat the high co2 that is suppressing your pH.

YOYOYOReefer · Feb 16, 2023

i think your ph is fine as well, but if you want to increase it try pulling outside air into your skimmer instead of air from the house.

Graemesreef · Feb 16, 2023

Dburr1014 said:
Alk @ 12, yikes

Exactly, raising the calcium and lowering the alk will aid in a more stable ph. IMO what he's doing to try to up the ph is working against him.

Randy Holmes-Farley · Feb 16, 2023

Graemesreef said:
Exactly, raising the calcium and lowering the alk will aid in a more stable ph. IMO what he's doing to try to up the ph is working against him.

Why do you think that lower alk will "stabilize" pH?

Higher alk causes higher pH at the same CO2 level.

Randy Holmes-Farley · Feb 16, 2023

CWH said:
I will add buffer to the tank - the pH will jump about 0.2-0.3 then it will come right back to >8 in a matter of an hour or so. I'll add kalk...same thing.

That's exactly as expected. No chemical raises pH and keeps it up.

FWIW, pH 7.9 is fine. Not perfect, but certainly acceptable.

The best you can do additive-wise is use hydroxide (like the kalkwasser; definitely not the buffer) if and when you need alkalinity. Buffers are usually among the worst choices to boost pH, except for things that cause no boost.

Other ways to boost pH include fresher air to the room, outside air piped to a skimmer inlet, a CO2 scrubber on a skimmer inlet, and more photosynthesis in the tank system (such as by macroalgae).