My experience - Kalkwasser causing High Alk & Calcium?

Starbuxxx · May 17, 2024

Sharing my experience for others that may be experiencing the same issue.

Basement 150g mixed reef lagoon with total water volume of about 225g

While struggling with low PH (7.7 - 7.8), I went through PH chasing journey and found the following solutions:
- DIY Co2 Scrubber
- Kalkwasser reactor dosing 7500/day to keep up with evaporation
- Open window
- Airstone in sump in running a line from outside (I have a second sump plumbed using a 40g brute and a bunch of live rock)
- Low profile fan blowing over the tank

These methods brought my PH highs reaching 8.41 and averaging 8.3. The downside was that my Alkalinity and Calcium was sky high. (Alk - 12.8 and Calc - 570)
I decided to taper off the Kalkwasser and see what my consumption was like without it. PH dropped to 8.15 avg and Alkalinity dropped - .50 dkH/day and Calc - .1 / day on average. My assumption is the lowered PH slowed down the calcium use.

Moving forward, I will introduce kalk back into the system with a weaker mix to keep the Alk balanced and give a ph boost. I'll also use a lower calcium salt for water changes until my tanks demand increases.

tzabor10 · May 17, 2024

Are you using Kalkwasser (or lime water as RHF calls it) as part of your ATO? I would not recommend that for the same reasons you mentioned. Perhaps dosing Kalk would give you more control

Starbuxxx · May 17, 2024

tzabor10 said:
Are you using Kalkwasser (or lime water as RHF calls it) as part of your ATO? I would not recommend that for the same reasons you mentioned. Perhaps dosing Kalk would give you more control

Yea, I'll have to separate the two. I tried to use a lower saturation of kalk as ATO but I'll take a more calculated approach.

exnisstech · May 17, 2024

I dosed kalk using a brs 50ml minute dosing pump and a cheap digital timer for a year or two on my 180g in my showcase. That and an occasional water change was all I did in that system and it did very well. I was dosing 7200ml daily of fully saturated kalk which was just a bit less than my evaporation rate. I can't comment on pH because I never noticed a bump when I compared it to my tanks not using kalk but I don't monitor pH I just tested a few times. Mine is always over 8 so I don't worry about it.

PS your dogs is awesome looking.

Randy Holmes-Farley · May 17, 2024

Clearly one should dose limewater (which is the English word for the German word kalkwasser) in just enough amount to maintain alk. Dising based on pH can lead to excessive alk.