kalkwasser dosing and precipitation

[TWYOUNG]

I would not worry too much about air getting in from a short mixing time. There’s no need to froth it, but stirring for 15 min will be fine.id cover whatever you store it in, but a trash can like lid is adequate.

I've started mixing in a trash can by running a power head for about 30 mins then covering with its lid. I dose from this with a dosing pump and it lasts about three weeks. Would it be beneficial to periodically run the power head to remix? I worry about settling from not mixing vs increased precipitation from more mixing. Some have suggested it's best not to disturb the scum which forms on the surface. I've even thought of floating a circular piece of styrofoam on the surface to minimize contact with air. If cut to a slightly smaller diameter than the trash can it could move with the water level.

 

[Randy Holmes-Farley]

I've started mixing in a trash can by running a power head for about 30 mins then covering with its lid. I dose from this with a dosing pump and it lasts about three weeks. Would it be beneficial to periodically run the power head to remix? I worry about settling from not mixing vs increased precipitation from more mixing. Some have suggested it's best not to disturb the scum which forms on the surface. I've even thought of floating a circular piece of styrofoam on the surface to minimize contact with air. If cut to a slightly smaller diameter than the trash can it could move with the water level.

No, there's no reason to remix it before it runs out. Dissolved calcium hydroxide cannot settle out. Only calcium carbonate solids will settle out, and there's no reason to dose that anyway.

 

[TWYOUNG]

No, there's no reason to remix it before it runs out. Dissolved calcium hydroxide cannot settle out. Only calcium carbonate solids will settle out, and there's no reason to dose that anyway.

Thanks! Sometime I think I'd like to do an experiment and collect and weigh all those leftover solids. It always seems like so much it concerns me I'm not getting enough calcium hydroxide dissolved in my water. My understanding is calcium hydroxide is quite poorly soluble in water.

 

[Randy Holmes-Farley]

Thanks! Sometime I think I'd like to do an experiment and collect and weigh all those leftover solids. It always seems like so much it concerns me I'm not getting enough calcium hydroxide dissolved in my water. My understanding is calcium hydroxide is quite poorly soluble in water.

I let a 1-2" thick mud develop over many years.

You can track potency of the kalkwasser very well by conductivity, and very crudely by pH.

 

[TWYOUNG]

I let a 1-2" thick mud develop over many years.

You can track potency of the kalkwasser very well by conductivity, and very crudely by pH.

I was aware of that but not sure I need to know badly enough to spring for a pricy conductivity probe lol!

 

[Randy Holmes-Farley]

I was aware of that but not sure I need to know badly enough to spring for a pricy conductivity probe lol!

Sure, I understand. But many people already have them to measure other things, such as salinity or RO/DI water, although inexpensive probes do not typically span the whole range from RO/DI to salinity.

 

[TWYOUNG]

Sure, I understand. But many people already have them to measure other things, such as salinity or RO/DI water, although inexpensive probes do not typically span the whole range from RO/DI to salinity.

I just watched a video from ACI Aquatics and he uses a pH probe to test the saturation of his kalk. He stated max saturation is a pH of 12.44 and as saturation drops so will pH. Could I use my Apex probe to test the pH of my kalk and if so what kind of a drop in pH would you consider significant?

 

[Randy Holmes-Farley]

I just watched a video from ACI Aquatics and he uses a pH probe to test the saturation of his kalk. He stated max saturation is a pH of 12.44 and as saturation drops so will pH. Could I use my Apex probe to test the pH of my kalk and if so what kind of a drop in pH would you consider significant?

pH is a very crude gauge of potency. A drop of 0.3 pH units is a 50% drop in potency. To use this method, you should make a for sure saturated solution (say, 2 tsp in a cup of ro/di) and compare pH to that. Relying on pH calibration will not be accurate enough.