Saturated limewater/kalkwasser/calcium hydroxide

[five.five-six]

How much calcium hydroxide do I really need per gallon of water to produce a fully saturated limewater solution?

 

[Flippers4pups]

1 1/2-2 teaspoons.

 

[five.five-six]

So, 3 Tbl spoons is all I need for a 5 gallons jug of DI watter?

 

[Flippers4pups]

So, 3 Tbl spoons is all I need for a 5 gallons jug of DI watter?

7 1/2 teaspoons, not tablespoons, is Max for 5 gallons.

1.5 x 5= 7.5

1 1/2 teaspoons is Max per gallon.

 

[Randy Holmes-Farley Verified Community Expert]

Solubility depends on temperature, but at 25 deg C you can dissolve exactly 1.5 grams per liter. How much dry volume that occupies varies a bit depending on how fluffy it is.

This has more:

What Your Grandmother Never Told You About Lime by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2005-01/rhf/index.htm

 

[five.five-six]

Many years ago, I would be very careful to make sure my pickup tube was at least an inch off the bottom of the limewater container. I didn’t have a RO/DI at the time and used the limewater to precipitate the impurities from tap water as prescribed by Craig Bingman circa 1990. I would use extra calcium hydroxide as I wanted to ensure there was enough to precipitate all the nasties.


Now tht I’m using 0ppm RO/DI water and have much more evaporation, I’m moving to waste not want not and trying to use s little as necessary.

 

[Randy Holmes-Farley Verified Community Expert]

I often added a big excess too. I'd just dump in a huge amount unmeasured and let the remainder sit on the bottom as mud. I'd stir till it got close to saturation based on conductivity, and then let it settle. Next time I could just stir it up again for a new batch.

 

[five.five-six]

It’s about an extra 5 minutes of work every week to make up the 10 gal of limewater tanks but I really don’t like the kalk stir connected to the RODI system for several reasons including TDS creep, and mechanical failure/flooded floor/brackish reef tank.

 

[five.five-six]

I often added a big excess too. I'd just dump in a huge amount unmeasured and let the remainder sit on the bottom as mud. I'd stir till it got close to saturation based on conductivity, and then let it settle. Next time I could just stir it up again for a new batch.

When you do that, how do you determine when your sludge has been exhausted?

 

[Randy Holmes-Farley Verified Community Expert]

When you do that, how do you determine when your sludge has been exhausted?

I was monitoring conductivity. If it wasn't coming up enough (to, say, 7.5 mS/cm or more) when stirring, I added more solids.

 

[Midrats]

I was monitoring conductivity. If it wasn't coming up enough (to, say, 7.5 mS/cm or more) when stirring, I added more solids.

Is there a conductivity meter you can recommend?

 

[Randy Holmes-Farley Verified Community Expert]

The Pinpoint salinity meter will work for this and for tank salinity, but a number of us, myself included, are quite happy with older Orion model 128 or similar devices if you can find one used with a good probe.