Diluting saturated Kalk...with fresh RO?

[YoubetyourWrasse]

Hello, simple question. I wanted to dilute a 1/2 saturated Kalk solution in my ATO. I noticed that my 180g is gaining 0.1-0.2 dkh daily with the current solution. Will adding RO to saturated kalk solution precipitate the rest out, I am sure it will lose potency simply d/t disturbing it, but will adding fresh water compound that greatly. Should I just eat the cost and mix a new batch at a lower potency or can I get away with simply diluting the solution with a somewhat marginal loss? I was thinking about displacing 5 gallons of my 15g ato with ro.

 

[Garf]

Hello, simple question. I wanted to dilute a 1/2 saturated Kalk solution in my ATO. I noticed that my 180g is gaining 0.1-0.2 dkh daily with the current solution. Will adding RO to saturated kalk solution precipitate the rest out, I am sure it will lose potency simply d/t disturbing it, but will adding fresh water compound that greatly. Should I just eat the cost and mix a new batch at a lower potency or can I get away with simply diluting the solution with a somewhat marginal loss?

It will make it weaker, unless you’ve got some undissolved Kalk at the bottom. Then in won’t make it quite as weak as you think. Kalk in ATOs is a bit worrisome to me.

 

[YoubetyourWrasse]

It will make it weaker, unless you’ve got some undissolved Kalk at the bottom. Then in won’t make it quite as weak as you think. Kalk in ATOs is a bit worrisome to me.

Yeah, a bit old fashioned and will put a stirrer on a dosing pump at some point. I have been siphoning out most precipitate actually. I am back from a 10 year hiatus in reefing for the past 7 months, but over a decade before I always put kalk in the sump without incident; however, I am aware of the danger and there are better options. This is fairly temporary. I am just wanting to know if adding fresh water will precipitate the Ca(HCO3)2 concentration out of the solution or it will hold some concentration at a lower saturation.

 

[Randy Holmes-Farley Verified Community Expert]

Yeah, a bit old fashioned and will put a stirrer on a dosing pump at some point. I have been siphoning out most precipitate actually. I am back from a 10 year hiatus in reefing for the past 7 months, but over a decade before I always put kalk in the sump without incident; however, I am aware of the danger and there are better options. This is fairly temporary. I am just wanting to know if adding fresh water will precipitate the Ca(HCO3)2 concentration out of the solution or it will hold some concentration at a lower saturation.

Old fashioned or not, I think dosing from a settled reservoir is better if you have room for it.

As noted above, adding fresh water dilutes it and reduces the potency. It cannot cause precipitation.

You also have the wrong chemical noted. You show calcium bicarbonate, but you are and should be using calcium hydroxide, Ca(OH)2.

 

[YoubetyourWrasse]

Old fashioned or not, I think dosing from a settled reservoir is better if you have room for it.

As noted above, adding fresh water dilutes it and reduces the potency. It cannot cause precipitation.

You also have the wrong chemical noted. You show calcium bicarbonate, but you are and should be using calcium hydroxide, Ca(OH)2.

Woops on the chemical, thanks. Yeah, I plan using a higher concentrated solution on a dosing pump independent of my ato resevoir and evaporation. Just not there yet, I have a few other priorities atm, then will move to that...it is on the longterm plan though. Thanks for your response. I didn't know if adding new water would cause a further reaction with more falling out of the solution. You answered my question.

 

[MnFish1]

Hello, simple question. I wanted to dilute a 1/2 saturated Kalk solution in my ATO. I noticed that my 180g is gaining 0.1-0.2 dkh daily with the current solution. Will adding RO to saturated kalk solution precipitate the rest out, I am sure it will lose potency simply d/t disturbing it, but will adding fresh water compound that greatly. Should I just eat the cost and mix a new batch at a lower potency or can I get away with simply diluting the solution with a somewhat marginal loss? I was thinking about displacing 5 gallons of my 15g ato with ro.

So to be clear - you mean you wanted to dilute a saturated kalk solution 1:2 - or you wanted to dilute a 1:2 solution to 1:4? Either way - The word saturated means that the maximum amount of Ca and OH is dissolved in the solution. The best way to make sure this is the case is that there is still undissolved chemical in the container. If you start trying to dilute this - you could also dissolve undissolved Kalk - such that you're really not dissolving it 1:2.