Chemistry Q - Alk high...will not come down.

[sscheitel]

90 Gal - New set up

Ca 400
Ph 8.3
Alk 5.17
Amm .10
Nitra .2
Nitri 0

(3) 40 Gal water changes done over the last 13 days

no movement

What could this be?

[whatevva]

Just Curious, what kind of salt are you using? IO?

[sscheitel]

Yes

IO...no buffering to the water at all.

IO with RO/DI water

[Wiskey]

Have you tested the alk in the salt? Are you sure your salinity is right? I had one of those swing arm hydro things, and it said I was at 1.024 when I was really at 1.030 which made perams always way on the high side when mixing salt.

HTH,
Whiskey

[whatevva]

I agree, Make sure the salinity is right, and you're testing with Salifert kits.

[Weatherman]

Good old IO.

Runs really high on the alk and pH and relatively low on the calcium.

I’m converting one of my tanks over from natural seawater to IO. The batch I’m using comes in with an alk of 4.29 and a calcium level of about 370 ppm. I’ve turned off my calcium reactor and kalk drip during the transition and am only dosing calcium chloride.

Not much you can do with high alk except either let it drift down by itself or use another salt mix with a lower alk. Tropic Marin is a good choice, but it's a bit expensive.

[sscheitel]

testing with Salifert...yes

I ruse have my swing meter...I really need to invest in a refractometer.