Can't get PH above 7.8

Richb5571

Community Member
View Badges
Joined
Dec 6, 2020
Messages
49
Reaction score
38
Location
Dripping Springs
Rating - 0%
0   0   0
I have a CO2 scrubber, a refugium and I dose 2 part solution daily with Apex DOS. Not sure what else to do. I have used aquavitro balance and PH goes up to 8.2 but 12 hrs later it settles back to 7.8
 
For your 2 part are you using soda ash? Soda ash raises ph better than sodium bicarbonate (use about half as much to get same Alk).
I would also check the calibration of the PH probe.

Also I would open the windows for a day and see if that raises your PH. If it does that would point to Co2 being the culprit.
 
For your 2 part are you using soda ash? Soda ash raises ph better than sodium bicarbonate (use about half as much to get same Alk).
I would also check the calibration of the PH probe.

Also I would open the windows for a day and see if that raises your PH. If it does that would point to Co2 being the culprit.
i just opened the windows today so I'm going to see if that has an impact. im using the BRS Soda Ash for my 2 part
 
so is it better to dose kalk vs. soda ash?
Kalk functions both as a alk raiser and a co2 reducer. If the scrubber is dialed in properly and recirculating, it should serve similar purposes used in conjunction with soda ash. However, often times, due to the size of the scrubber/skimmer vs the surface area of the dt/sump/overflow and ambient air exchange thats pumping co2 back into the system, kalk has an easier time raising pH if the scrubber/skimmer is undersized for air exchange purposes.

Kalk users sometimes has to opposite problem - ph too high, leading to burnt tips and abiotic precipitation
 
Kalk functions both as a alk raiser and a co2 reducer. If the scrubber is dialed in properly and recirculating, it should serve similar purposes used in conjunction with soda ash. However, often times, due to the size of the scrubber/skimmer vs the surface area of the dt/sump/overflow and ambient air exchange thats pumping co2 back into the system, kalk has an easier time raising pH if the scrubber/skimmer is undersized for air exchange purposes.

Kalk users sometimes has to opposite problem - ph too high, leading to burnt tips and abiotic precipitation

Kalk is more of a alk holder than a raiser. Using something like Reef Fusion 2 to raise it, then kalk to hold it there is better. You just have to slowly raise it.
 
Kalk is more of a alk holder than a raiser. Using something like Reef Fusion 2 to raise it, then kalk to hold it there is better. You just have to slowly raise it.

Doesn't the hydroxide provided by kalk strip out the dissolved CO2 to form carbonate and bicarbonate? Thus raising Alk?

Always thought the apparent decrease in Alk from kalk is the result of increase in alk consumption from calcification /precipitation due to pH increase instead.

Either way, agree when using kalk, supplemental alk dosing should be mainly bicarbonate since soda ash can cause too much ph impact.
 
There are multiple factors that determine PH in a reef, but they all are based off of CO2 is the water column. The biggest predictor is ambient CO2 in the house air. Opening a window helps this, but depending on how high it is, the tank ph can drop as much as 0.3. I invested in a CO2 monitor for my house and it helped quite a bit.

Another major factor is biological. Highly stock tanks will have more CO2. But more than that, bacteria produce CO2 when processing waste. Extra food or built up detritus can have major effect on the PH. The sand bed can effect this, but a more common problem is a dirty filter/sump. A lot of detritus can get trapped in the rocks as well. Using a turkey baster to blow them out can pull out a lot of detritus.

If weather allows, I would recommend continuing to air out the house. Then focus on cleaning out the tank. I recommend not doing a mass cleaning, but focus on a section at a time.
 

IF YOU HAD TO TAKE A REEFING EXAM, WOULD YOU PASS?

  • Yes!

    Votes: 32 45.7%
  • Not yet, but I have one that I want to buy in mind!

    Votes: 9 12.9%
  • No.

    Votes: 26 37.1%
  • Other (please explain).

    Votes: 3 4.3%
Back
Top