Kalk Question

cadmanof50s

New member
I use Kalk in my Automatic top off system. I have a 5 gallon container to which I add 8 teaspoons of Kalk to 5 gallons.
Water is drawn from the container at a point above the sludge so it doesn't get into the system.

Does this sludge need to be stirred up every once in a while to help it dissolve and make the water above it retain it's high pH value?

Also, quite often, rather than dumping the sludge, I merely fill the container with RO water. This usually stirs up the sludge and I don't bother adding anymore kalk to the container. I wait till 10 minutes for it to settle and then start the ATO system up again....is this a good idea or should I dump the sludge and start off fresh every time?

Vic
 

downbeach

New member
I usually make my kalk in a separate container, allow it to settle overnight, and pour the settled limewater into my ATO the next evening. I don't throw what's left in the mixing container out, I just add more RO/DI water and Kalk, stir it up, and do the whole process all over again.
 

AdamSabina

New member
No you do not need to mix the five gallon jug after it's stirred the first time. I wash the old sludge out every time I refill. My calcium is 410 and alk is 8.5-8.7 DKH. No issues yet. Less work and equipment the better in my opinion.

Are you doing LPS or SPS?
 

AdamSabina

New member
I usually make my kalk in a separate container, allow it to settle overnight, and pour the settled limewater into my ATO the next evening. I don't throw what's left in the mixing container out, I just add more RO/DI water and Kalk, stir it up, and do the whole process all over again.

+1 that's a nice way to do it. I am going to try it for me, but won't he run into saturation levels. He's only running 8 tsp be 5 gallons not ten.
 

tmz

ReefKeeping Mag staff
Premium Member
I use Kalk in my Automatic top off system. I have a 5 gallon container to which I add 8 teaspoons of Kalk to 5 gallons.
Water is drawn from the container at a point above the sludge so it doesn't get into the system.

Does this sludge need to be stirred up every once in a while to help it dissolve and make the water above it retain it's high pH value?


No continuous stirring is needed or desired in that set up. The sludge is precipitated impurities. It can also contain extra undissolved calcium hydroxide when more than 2 tsps per gallon is added. At less than 2 teaspoons per gallon there should be no undissolved kalk in the slurry.

In a covered still reservoir ,the limewater( kalk) will hold it's full strength for several weeks to a month. Stirring , agitates the surface drawing in CO2 from the surounding air .THe CO2 binds with the oxide to form carbonate and then with calcium ,precipitating out as calcium carbonate .This weakens the limewater.

Also, quite often, rather than dumping the sludge, I merely fill the container with RO water. This usually stirs up the sludge and I don't bother adding anymore kalk to the container. I wait till 10 minutes for it to settle and then start the ATO system up again....is this a good idea or should I dump the sludge and start off fresh every time?

Add more kalk each time you refill, the slurry won't add any calcium hydroxide unless you dose more than 2 tsps pr gallon initially. It's ok to mix in th slurry when you refill and add new kalk powder ;just let it settle for 1 to 2 hours before starting to dose it.

You can clean out he slurry as often or infrequently as you like when refilling if you let it resstlle before dosing. I scoop some out of my reservoir every few months just to be sure the tube drawing the kalk remains clear of it.

Vic
 

tmz

ReefKeeping Mag staff
Premium Member
I use Kalk in my Automatic top off system. I have a 5 gallon container to which I add 8 teaspoons of Kalk to 5 gallons.
Water is drawn from the container at a point above the sludge so it doesn't get into the system.

Does this sludge need to be stirred up every once in a while to help it dissolve and make the water above it retain it's high pH value?


No continuous stirring is needed or desired in that set up. The sludge is precipitated impurities. It can also contain extra undissolved calcium hydroxide when more than 2 tsps per gallon is added. At less than 2 teaspoons per gallon there should be no undissolved kalk in the slurry.

In a covered still reservoir ,the limewater( kalk) will hold it's full strength for several weeks to a month. Stirring , agitates the surface drawing in CO2 from the surounding air .THe CO2 binds with the oxide to form carbonate and then with calcium ,precipitating out as calcium carbonate .This weakens the limewater.

Also, quite often, rather than dumping the sludge, I merely fill the container with RO water. This usually stirs up the sludge and I don't bother adding anymore kalk to the container. I wait till 10 minutes for it to settle and then start the ATO system up again....is this a good idea or should I dump the sludge and start off fresh every time?

Add more kalk each time you refill, the slurry won't add any calcium hydroxide unless you dose more than 2 tsps pr gallon initially. It's ok to mix in th slurry when you refill and add new kalk powder ;just let it settle for 1 to 2 hours before starting to dose it.

You can clean out he slurry as often or infrequently as you like when refilling if you let it resettle before dosing. I scoop some out of my reservoir every few months just to be sure the tube drawing the kalk remains clear of it.

Vic
 

cadmanof50s

New member
Thanks for all the great responses.

For some reason, I assumed that the sludge needed to be agitated infrequently. But this makes a lot of sense.

I will add kalk every time I refill the ATO container and clean out the sludge once its starts getting too close to the intake.

Great info, thanks again!

Vic
 

blanden.adam

Team RC
I'm with Tom on this one. I'd just echo his advice and give you this article by RHF, which is at the top of my "MUST READ" list for anyone dosing limewater for their reef:

http://www.reefkeeping.com/issues/2005-01/rhf/#8

In reference to a previous comment I would also just say that a large still reservoir is the best method for dosing limewater if space is not an issue. Kalk stirrers can be useful if space is a concern, but it is by no means a superior technology. Both can certainly be used effectively, I just didn't want you to get the idea that it was "best practice" to use a kalk stirrer and make immediate plans to switch. :) They are expensive, have extra moving parts, and even when performing optimally can only match but never surpass a still reservoir in performance.
 

cadmanof50s

New member
Just wanted to give an update on this post.

Ever since I have been adding kalk on a regular basis when refilling my ATO, I have been able to keep very good control of the ph levels. So now instead of just adding RO water to the sludge, I add 8 teaspoons for every 5 gallons I top up.

Now. I use my tank controller in conjunction with the ATO/kalk and I can beep the ph at a steady 8.2 during the day and 8.0 at night.

Thanks for the guidance.

Vic
 
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