solubility of calcium hydroxide and heat

salty joe

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I'm considering adding a heater to my DIY kalk reactor.
We keep our place at 59 at night and when we are not home which is most of the time, otherwise 68. The average temp in my kalk reactor is probably the low 60s. I have a titanium heater that says it will heat up to 93.
If I were to heat things up to 93 before a stir cycle and get a more concentrated solution, would the solution become less concentrated when the temp falls back to the low 60s?
How much more concentrated would a solution be at 93 compared to 63?
 
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salty joe

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Maybe an iceprobe chiller will help for the summer. We keep things on the warm side in summer.
If I chilled the kalk reactor down to 60 before a stir cycle then over the course of a day the temp climbed to 80, would calcium hydroxide likely fall out of solution?
 
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salty joe

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I'm making a new kalk reactor to fit inside the mini fridge that I use to dose frozen food. With the temp just above freezing, the kalk should be about 15% stronger, at least in the summer when the kalk would often be 80 degrees.

Am I safe to assume a saturated kalk solution at 33 degrees would have a higher pH than a saturated solution at 80 degrees?
 

Randy Holmes-Farley

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Maybe an iceprobe chiller will help for the summer. We keep things on the warm side in summer.
If I chilled the kalk reactor down to 60 before a stir cycle then over the course of a day the temp climbed to 80, would calcium hydroxide likely fall out of solution?

Some will. The curve of solubility is not especially steep:


1612819927607.png
 
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salty joe

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I had the kalk reactor in the same cabinet as the mini fridge so it was getting heated a little. Might as well put in the fridge, every little bit helps.
Thanks again for pointing out that kalk is more soluble in cold water. Seems counter intuitive.
 
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