Alkalinity decline without coral

GARRIGA · Sep 29, 2022

Nitrification reduces alkalinity and carbon dosing or denitrification puts it back although WCs will remove the nitrates produced and not allowed to replace what was used during nitrification. Perhaps reducing nitrates before performing a WC will help. I don't do WCs in my test tank and my alkalinity is stabilized around 9 dkh and coming up on a year since last WC. Carbon dose and have a large media bed that is suppsoed to perform dentrification but flow appears to fast but it's working. Hope is once I have my main with corals then only replenishment will be that consumed and not due to nitrification.

keithIHS · Sep 29, 2022

Randy H-F was confident it was going into the sand. I think I recall that conversion of ammonia to nitrate reduces alk and conversion of nitrate to N2 (or uptake of nitrate by algae etc?) increases alk, which is why my dosing nitrate was increasing my alk, and why dosing ammonia is supposed to have no net effect on alk.

SeptorsReef · Dec 19, 2024

Randy Holmes-Farley said:
If you want a pH boost, use sodium carbonate/baked baking soda/soda ash.

If you do not want a pH boost, use sodium bicarbonate/baking soda.

If you do not know your pH, just pick one at random. :)

I'm glad I ran onto this thread because I'm in the same boat here (even the same time frame). My current alk is 5.5 dkh and Ph stays around 7.7-7.8 with Co2 scrubbers. Can I start dosing kalkwasser now, as I was preparing myself for corals later and never thought i would need to dose anything yet. I have the Apex and do 10% weekly water changes, using Tropic Marin Pro Reef salt. If not, do I dose baking soda the same as the BRS soda ash calculator? Thanks!

Randy Holmes-Farley · Dec 19, 2024

SeptorsReef said:
I'm glad I ran onto this thread because I'm in the same boat here (even the same time frame). My current alk is 5.5 dkh and Ph stays around 7.7-7.8 with Co2 scrubbers. Can I start dosing kalkwasser now, as I was preparing myself for corals later and never thought i would need to dose anything yet. I have the Apex and do 10% weekly water changes, using Tropic Marin Pro Reef salt. If not, do I dose baking soda the same as the BRS soda ash calculator? Thanks!

You can use kalk now, but don’t try to raise the alk too fast with it.

Reefer Tom ATX · Jan 22, 2025

Randy Holmes-Farley said:
You can use kalk now, but don’t try to raise the alk too fast with it.

This is a very helpful thread and already learned a lot, thanks. I just setup my 164g RS S-700 using Marco Rock and Caribsea live sand 6 weeks ago. This is my second tank, coming from a biocube 32.. I was also surprised by the alk consumption on the new tank. I use reef crystals which has a high alk, but only increasing alk by .2 each day dosing 60ml of BRS soda ash daily trying to get to 9dkh. I have 7 fish, zero inverts or coral, lights off, and uv/skimmer/reef mat running. Phosphate .08 Nitrate 12.3 PH 7.9 I just bought the Avast Kalk stirrer that I plan on setting up in a few weeks as I've had great success with kalk on my Biocube.

Any suggestions on how to minimize the alk loss while I wait to turn on the light and move my corals over? Should I just keep dosing the liquid soda ash?

Randy Holmes-Farley · Jan 22, 2025

Reefer Tom ATX said:
This is a very helpful thread and already learned a lot, thanks. I just setup my 164g RS S-700 using Marco Rock and Caribsea live sand 6 weeks ago. This is my second tank, coming from a biocube 32.. I was also surprised by the alk consumption on the new tank. I use reef crystals which has a high alk, but only increasing alk by .2 each day dosing 60ml of BRS soda ash daily trying to get to 9dkh. I have 7 fish, zero inverts or coral, lights off, and uv/skimmer/reef mat running. Phosphate .08 Nitrate 12.3 PH 7.9 I just bought the Avast Kalk stirrer that I plan on setting up in a few weeks as I've had great success with kalk on my Biocube.

Any suggestions on how to minimize the alk loss while I wait to turn on the light and move my corals over? Should I just keep dosing the liquid soda ash?

Make sure the sand isn't hardening from precipitation, and if corals are not there yet, just keeping it at 7 dKH will reduce consumption for now.

Reefer Tom ATX · Jan 22, 2025

Randy Holmes-Farley said:
Make sure the sand isn't hardening from precipitation, and if corals are not there yet, just keeping it at 7 dKH will reduce consumption for now.

Sand isn't hardening, but I do have this on the pump brackets. Is this precipitation? Doesn't look like coraline. Nothing else growing anywhere in the tank.

Randy Holmes-Farley · Jan 22, 2025

Reefer Tom ATX said:
Sand isn't hardening, but I do have this on the pump brackets. Is this precipitation? Doesn't look like coraline. Nothing else growing anywhere in the tank.

I would not assume that is precipitation, but it might be if there were deposits already there.