High Alk!!!

wiltzlan · May 2, 2016

I'm having one hell of an issue getting Alk down in my tank. I have a 300g no dosing because I don't have many corals after the great crash of 2015, weekly water changes of about 25g. Alk was over 14 but is now at 11.8. I have no idea how it got so high but I did switch salts afterwards. I'm now using Fluval Sea Salt and Alk is going down. But after about 200 gallons of water changes, Alk is still at 11.7-11.8. Is there another way to bring the Alk down quicker? CA 450, Mg 1350.

jsker · May 2, 2016

Could it be possible that your salt has a high alk? And the is keeping your alk high. I was running a high alk and switched to a lower alk salt and my alk is finely dropping into the 9's. I am also dosing the balling method and cut my alk dose way back till I hit the 8.5 mark.

wiltzlan · May 2, 2016

jsker said:
Could it be possible that your salt has a high alk? And the is keeping your alk high. I was running a high alk and switched to a lower alk salt and my alk is finely dropping into the 9's. I am also dosing the balling method and cut my alk dose way back till I hit the 8.5 mark.

That's what I thought and the reason why I switched from Salinity to Fluval salt. The Alk level has been going down since but it is still taking a long time. I've replaced about 66% water volume and I'm still over 11dKH.

Randy Holmes-Farley · May 2, 2016

Unless this is a ULNS SPS tank (and since alk is not lowering I presume it is not), there's no concern about that alkalinity level.

It can be lowered with an acid, but I wouldn't.

wiltzlan · May 2, 2016

Thanks Randy. I was just worried because my other SPS don't look so hot. Not having any with burnt tips anymore but still not getting good polyp extension on them.

luke33 · May 2, 2016

If your sps are still hanging on after having an alk of over 14 and now your down to 11.8 I would just let them slowly get down to 9 and then keep your alk consistent. Are you sure your test kit is accurate?

wiltzlan · May 2, 2016

Yes. I used a Red Sea kit, Hanna Checker and had the LFS check it.

Randy Holmes-Farley · May 2, 2016

wiltzlan said:
Thanks Randy. I was just worried because my other SPS don't look so hot. Not having any with burnt tips anymore but still not getting good polyp extension on them.

If nutrients are not low, then most SPS actually grow faster at higher alk.

wiltzlan · May 3, 2016

Thanks Randy. I guess I'll just keep doing the weekly water changes and let the tank settle at whatever Fluval SEA Salt mixes at. Once there, I'll start dosing a little if needed to keep it at that level. I just didn't want to lose the shipment from BattleCorals that I have coming in this week. Thanks again everyone.