Concerned about High PH with Kalk dosing

[b4tn]

I recently switched to kalkwasser because I was having trouble keeping things balanced with two part. I really like that my levels are near perfectly balanced at 420ppm Calc and and 8.4 Alk. Its never been so solid ever. I am surprised that with what I thought was was low demand 5 SPS colonies, A huge zoa colony, Duncan colony, scattered brain corals, and rapid coraline growth that my usage is almost 1.4 Dkh per 24 hours.

But I noticed the other day the tips of my stylo which are close to my return in the display looking burnt. I add the kalk to the return chamber in my sump. That being said I started looking at my PH. I am using a BRS lab grade probe and getting 8.68 max at the end of the day and 8.5 at night and that seems really high to me! I am dosing 90ml of saturated Kalk every hour so thats 2160 ml every 24 hours which is very close to my evaporation. I looked at adding vinegar to the Kalk to help bring down the PH and lower the amount dosed but I am worried about bacteria from a carbon source. Any other suggestions? I do skim but also have a very well established algae scrubber that gets light 20 hours a day.

 

[cmcimino]

Have you thought about dosing Kalk to your ATO reservoir? I start at .5 tsp per gallon. Check your alk every day or so, if it drops, bump the dosage up.

 

[b4tn]

Have you thought about dosing Kalk to your ATO reservoir? I start at .5 tsp per gallon. Check your alk every day or so, if it drops, bump the dosage up.

Thats essentially what I am doing now. My dosing almost exactly matches my evap rate and my ATO rarely comes on anymore. I chose to dose over adding to the ATO so I had more control over how much was added vs the unpredictability of a changing evaporation rate.

 

[Randy Holmes-Farley Verified Community Expert]

More aquarium aeration will lower the pH, as would organic carbon addition to the tank.

 

[Neoalchemist]

I recently switched to kalkwasser because I was having trouble keeping things balanced with two part. I really like that my levels are near perfectly balanced at 420ppm Calc and and 8.4 Alk. Its never been so solid ever. I am surprised that with what I thought was was low demand 5 SPS colonies, A huge zoa colony, Duncan colony, scattered brain corals, and rapid coraline growth that my usage is almost 1.4 Dkh per 24 hours.

But I noticed the other day the tips of my stylo which are close to my return in the display looking burnt. I add the kalk to the return chamber in my sump. That being said I started looking at my PH. I am using a BRS lab grade probe and getting 8.68 max at the end of the day and 8.5 at night and that seems really high to me! I am dosing 90ml of saturated Kalk every hour so thats 2160 ml every 24 hours which is very close to my evaporation. I looked at adding vinegar to the Kalk to help bring down the PH and lower the amount dosed but I am worried about bacteria from a carbon source. Any other suggestions? I do skim but also have a very well established algae scrubber that gets light 20 hours a day.

Was wondering how you finally solved this problem. I'm in exactly the same boat, ph approaching 8.6 at the end of the day but my numbers never looked better.
I unfortunately an living with the threat of dinoflagellates. So I won't be carbon dosing.

 

[b4tn]

Was wondering how you finally solved this problem. I'm in exactly the same boat, ph approaching 8.6 at the end of the day but my numbers never looked better.
I unfortunately an living with the threat of dinoflagellates. So I won't be carbon dosing.

I ended up going back to dosing two part.