Help with dosing Kalkwasser.

[That_One_Brodie]

I am looking to start dosing kalwasser for my tank. As I am struggling to keep Alk above 7 dKH. I have a nuvo 10 with with LPS/Softies. I have been dosing Seachem Reef Fusion 2, however that was 2-3 ml a week (stopped this week to measure Alk demand, seen below). I'm hoping to keep my Alk at 9. But my biggest goal is to maintain it at a certain level, rather that having these steep fluctuations I'm currently experiencing (in the past Alk has gotten to the low 5's!). I measured my rate of evaporation over a 24 hour period, it's approximately 800ml a day.

I have tested my tank for the past 5 days to get my Alk demand:
March 1st - 8.3
March 2nd - 7.7
March 3rd - 7.3
March 4th - 6.7
March 5th - 6.4

Using the Reef Chemistry Calculator I got the following dose to raise my Alk. Stating to add 7.9 ml to get my Alk from 6.4 to 9. However I am unsure how much to dose on a daily basis to maintain 9 dKH. I am planning on using a dosing pump with a separate container of pre-mixed kalwasser (thinking of using the BRS kalwasser mix).

Question: How would I go about calculating the daily dose for Alk to maintain a level of 9dKH?

Some other information I think that is useful: Mg has been 1230/1260 and Ca has been 420. I use reef crystals for my tank and do about a 2.5g to 3g water change weekly. Going to tone it down to 1-1.5g weekly water changes. I think that has a factor or my Alk issue. Tank has been going since August 2022.

Bonus shot of my tank included

 

[MoshJosh]

If I am understanding everything correctly. . .

Using the calculator based on your daily Alk drop (8.3 to 7.7) , it looks like you need "0.05 US gallons; 0.19 Liters; 6.7 fl oz" of fully saturated limewater daily to maintain your levels. . .

I would use that as a starting point for daily dosing. . . so use the calculator and get whatever your Alk is now up to your desired level of 9 (you can uses the Fusion B to do this), then start dosing kalk daily based on the above.

All that being said, your tank is looking awesome so it is hard to advise changing anything haha

 

[That_One_Brodie]

If I am understanding everything correctly. . .

Using the calculator based on your daily Alk drop (8.3 to 7.7) , it looks like you need "0.05 US gallons; 0.19 Liters; 6.7 fl oz" of fully saturated limewater daily to maintain your levels. . .

I would use that as a starting point for daily dosing. . . so use the calculator and get whatever your Alk is now up to your desired level of 9 (you can uses the Fusion B to do this), then start dosing kalk daily based on the above.

All that being said, your tank is looking awesome so it is hard to advise changing anything haha

That makes sense. Would be about 190ml a day. Which is way under my daily evaporation, I have heard you don't want to exceed daily evaporation when dosing kalkwasser.

Haha yeah it looks good, but trying to get better growth and stability in parameters.

 

[MoshJosh]

That makes sense. Would be about 190ml a day. Which is way under my daily evaporation, I have heard you don't want to exceed daily evaporation when dosing kalkwasser.

Haha yeah it looks good, but trying to get better growth and stability in parameters.

Yeah, I think the worry is you will throw off your salinity if you exceed your evaporation.