Alkalinity question

Mdbbears34 · Jul 18, 2018

Over the weekend I raised my alkalinity to 8.4 tested the tank tonight with hanna alk checker and red sea pro it dropped to 8 on the hanna and 7.9 on the red sea. My question is I only have 1 Lps frag in my tank 2 large colonies of zoas and a lot of coraline. My calcium also tested tonight was 420 red sea and 434 on hanna, has not dropped at all so do I dose alkalinity and not calcium or dose equal parts until it stabilizes. Mag is at 1500 red sea which I do not believe, i checked with an older but not out of date sailifert and it was at 1350. The tank has been up and running for six years. The last time I had coral in it was a year and a half ago, then I screwed up doseing and not testing my water change parameters, everything went south. So I gave up for a bit. Don't want to make the same mistake. Any help would be appreciated.

Randy Holmes-Farley · Jul 18, 2018

Mdbbears34 said:
Over the weekend I raised my alkalinity to 8.4 tested the tank tonight with hanna alk checker and red sea pro it dropped to 8 on the hanna and 7.9 on the red sea. My question is I only have 1 Lps frag in my tank 2 large colonies of zoas and a lot of coraline. My calcium also tested tonight was 420 red sea and 434 on hanna, has not dropped at all so do I dose alkalinity and not calcium or dose equal parts until it stabilizes. Mag is at 1500 red sea which I do not believe, i checked with an older but not out of date sailifert and it was at 1350. The tank has been up and running for six years. The last time I had coral in it was a year and a half ago, then I screwed up doseing and not testing my water change parameters, everything went south. So I gave up for a bit. Don't want to make the same mistake. Any help would be appreciated.

You cannot make calcium decisions based on 1 day.

With a real alk drop of 0.4 dKH per day, calcium will only drop by about 2.5 ppm, which you cannot reliably detect by kit.

I see no reason to not dose equal parts to maintain alk (and by inference, calcium), as long as you are using a product designed for 1:1 dosing (not all are).

Mdbbears34 · Jul 18, 2018

The .4 drop was over 3 days. And I'm useing brs 2 part. So to raise alkalinity back to 8.4 the reef chemistry calculator says to add 37.1ml. So I would devide by 3 since the drop accured over a 3 day period? Which would be 12.3 ml per day of both calcium and alkalinity. If I am off please tell me lol.

Flippers4pups · Jul 18, 2018

Within 1 dkh a day is safe. .04 is perfectly fine.

Randy Holmes-Farley · Jul 18, 2018

Mdbbears34 said:
The .4 drop was over 3 days. And I'm useing brs 2 part. So to raise alkalinity back to 8.4 the reef chemistry calculator says to add 37.1ml. So I would devide by 3 since the drop accured over a 3 day period? Which would be 12.3 ml per day of both calcium and alkalinity. If I am off please tell me lol.

Yes.