Kalkwasser set up

Mathieu Lafleur · Dec 5, 2020

Hi there,

I will be setting up a kalkwasser stirrer tomorrow for my 180gal after years of simply having 3 parts supplement my tank. I was wondering if anyone had a calculator for how much should I be dosing considering I've got a 0.9 ish DKH consommation per day. I found a few calculator but they were for systems delivering kalk from a bucket using ATOs. In my case I'll be using a doser to dose in order to effectively course correct If needed. I simply want to know I much should I be starting with in order not crash my tank with either a PH spike or with DKH bottoming out?

Thanks all and happy reefing,

AZMSGT · Dec 5, 2020

Back when I set up my Calc stirrer I couldn’t find a good answer to this. So I figured out how much evaporation my tank did over a 24hr period and then dosed the water through the stirrer at 50% of daily evaporation. I had it programmed to stir for 15 minutes and then shut off for 15 minutes then dose. I checked DKH with automatic testing 4 times a day and would adjust the qty based off readings. Yea I had small PH swings but it never effected growth.

Garf · Dec 5, 2020

I wouldn’t have thought the saturation level of kalk in a stirrer would be much different to a bulk reservoir, like an ATO. The calculator you found is probably about right. Just start a bit less and test your Alk.

chinw76 · Dec 5, 2020

I used to do 2 part, never really needed magnesium. I was scarred of kalkwasser because I heard of some stories of tank crashes. What I do is I put it in my ATO water. If your levels are were you want them before Kalk, what I would do is start with 1 tsp per gallon of water. Test in a week, and if you levels are falling, then goto 1.5 tsp of kalk per gallon of water. Use your 2 part solution to bring the levels were you want them at. Test in a week, if your levels are holding then you know how much kalk to add every week. I keep 2 part solution to raise my levels as needed. The ATO keeps my levels fairly level and keeps my ph between 8.2 to 8.5. In my opinion, using it in an ATO is the easiest way of dosing it to your system. Sorry I couldn't be anymore help, but don't be afraid like I was about the tank crashing.

dwest · Dec 5, 2020

Mathieu Lafleur said:
Hi there,

I will be setting up a kalkwasser stirrer tomorrow for my 180gal after years of simply having 3 parts supplement my tank. I was wondering if anyone had a calculator for how much should I be dosing considering I've got a 0.9 ish DKH consommation per day. I found a few calculator but they were for systems delivering kalk from a bucket using ATOs. In my case I'll be using a doser to dose in order to effectively course correct If needed. I simply want to know I much should I be starting with in order not crash my tank with either a PH spike or with DKH bottoming out?

Thanks all and happy reefing,

Based on my 180 and it’s kalk consumption, you will need to dose about 4L of kalk per day. I would start with about half that, monitor alkalinity carefully and adjust from there.

Randy Holmes-Farley · Dec 5, 2020

1.42 gallons of saturated limewater will add 0.9 dKH to 180 gallons of water volume.

A stirrer may or may not reach saturation, but starting near this level and raising it if needed sounds like a good plan.

Mathieu Lafleur · Dec 5, 2020

dwest said:
Based on my 180 and it’s kalk consumption, you will need to dose about 4L of kalk per day. I would start with about half that, monitor alkalinity carefully and adjust from there.

How would that much affect PH?

Randy Holmes-Farley · Dec 5, 2020

Mathieu Lafleur said:
How would that much affect PH?

Adding 1.25% of the tank volume in saturated limewater will instantly boost pH by around 0.65 pH units.

But since it is spread out, the rise is far smaller as aeration brings in CO2 to lower it constantly. Very few reef aquaria will get pH too high using limewater.

Mathieu Lafleur · Dec 5, 2020

Randy Holmes-Farley said:
1.42 gallons of saturated limewater will add 0.9 dKH to 180 gallons of water volume.

A stirrer may or may not reach saturation, but starting near this level and raising it if needed sounds like a good plan.

Thanks so much Randy, I was secretly hopping you would answer my post loll.
How can I do that calculation myself and how would that affect my PH? Thanks again!!