Can't lower Alkalinity

[jjb]

Hello. I'm using BRS Soda Ash and Calcium Chloride. My alkalinity keeps rising, I've lowered the soda ash dosing amount slowly and now it's down to 0 but the Alk is at 14.6 and rising (both Trident and Hanna agree). Corals seem pretty happy. CA is falling at about 264 even with a pretty good dose of Calcium Chloride (100mL/day).

I do 10% a week water change with Red Sea salt.

Jeff

 

[billwill]

Your alk is rising because you're overdosing it. Calculators are a rough starting point; you need to do daily testing to fine tune your dosing until you find the sweet spot that keeps it constant. Stop dosing alk and let it slowly get back to where you want it.

 

[Randy Holmes-Farley Verified Community Expert]

Try your kits on some new salt water. I cannot see how you got to this point unless you dosed a lot of alkalinity and little or no calcium.

 

[jjb]

I've been dosing 0mL Alk for about a week and it's still rising.

 

[jjb]

Good point on the new water test, I'll try that.

 

[Randy Holmes-Farley Verified Community Expert]

I've been dosing 0mL Alk for about a week and it's still rising.

How much in a week?

Here's a post of mine from another thread today:

Alkalinity can rise for a number of reasons, and in a tank with little to no demand, these minor processes become more apparent.

Declining nitrate will boost alkalinity, some additives will boost it when they claim not to or do not mention it, and sand and rock can slowly dissolve deep down inside them where the pH may be low enough due to organic degradation to dissolve some calcium carbonate.

 

[Twitchy]

what's your PH at?

 

[jjb]

That is interesting Randy. The tank is pretty low-demand and I dose NeoPhos but Nitrates stay very low, maybe that has something to do with it.

Water change tub measures 8.1 so that's not it.

Ph is pretty steady between 8.1 and 8.2 (as per both Hanna and Apex).

 

[Randy Holmes-Farley Verified Community Expert]

what's your PH at?

Why are you asking that?