Kalkwasser in ATO. How do you keep it stable?

[jayteerq]

Hey guys. I have over 70 pieces of coral in my 6 month tank. Mostly all LPS but definitely have some beginner SPS and anemones and 5” clam as well. I’ve been dosing saturated kalk since the start and am not seeing much uptake of my Alk and Cal. I know LPS don’t require Alk and Cal but do they atleast use any bit at all? I want to eventually switch to Kalkwasser in my ATO just to make maintenance more simplified but I’m worried it’ll make my Alk shoot through the roof. I’m dosing less kalk than I’m evaporating water currently. Currently dosing 600mL of kalk per day. Keeps me at a stable 9dkh. I estimate I evaporate about 1200mL per day.

I’m just curious, for those with Kalkwasser in ATO. Is this method only for those who will use up all the parameters and you just use it for foundation? Then dose additional things for shipment? Or does the kalk eventually balance out the parameters?

 

[bobnicaragua]

You can use kalk in your ATO, just experiment with the amount per gallon. (Mix it weak) Evaporation rates vary, so this isn’t the best method.

I use a versa to dose a constant rate of kalk, and have a small ATO to make up the difference.

 

[jayteerq]

You can use kalk in your ATO, just experiment with the amount per gallon. (Mix it weak) Evaporation rates vary, so this isn’t the best method.

I use a versa to dose a constant rate of kalk, and have a small ATO to make up the difference.

Yeah I might just stick to my method as well lol

 

[Randy Holmes-Farley Verified Community Expert]

I used it this way for 20 years. If you match the amount of solid added to the water to the demand, things can be stable, aside from changes to evaporation on a daily or seasonal basis.

There is a negative feedback loop that helps stabilize parameters because higher alk and higher pH boosts alk demand, so trying to stabilize things is easier than it might seem without trying it.

 

[jayteerq]

I used it this way for 20 years. If you match the amount of solid added to the water to the demand, things can be stable, aside from changes to evaporation on a daily or seasonal basis.

There is a negative feedback loop that helps stabilize parameters because higher alk and higher pH boosts alk demand, so trying to stabilize things is easier than it might seem without trying it.

Oh wow interesting. How does higher alk create alk demand? Also with that being said how long could it take to stabilize? Does it bother the corals in the process with alk all over the place? I’m wondering if kalk in ATO is for me or if I should just keep what I’m doing now

 

[Randy Holmes-Farley Verified Community Expert]

Oh wow interesting. How does higher alk create alk demand? Also with that being said how long could it take to stabilize? Does it bother the corals in the process with alk all over the place? I’m wondering if kalk in ATO is for me or if I should just keep what I’m doing now

I don't think it takes any special time to "stabilize" any more than any other additive method. Just start by dosing an amount that is reasonably close to daily demand, or get there rapidly by monitoring alk and adjusting potency by trial and error.

Both coral calcification rates and abiotic precipitation of calcium carbonate go faster at higher alk and higher pH. That offsets imperfections in amount dosed.