Kalk water stirring

Fishfinder · Jul 25, 2018

does kalk water have to be regularly stirred? Will it stay saturated without be stirred for a week?

ncaldwell · Jul 25, 2018

Nope, once stirred the water will become saturated and the rest will fall out of solution. Once the liquid is used up to about an inch from the slurry on the bottom I clean the container and make more.

kswan · Jul 25, 2018

I was wondering this too. I mix up 4 gallons of saturated solution and use a dosing pump. It lasts about 1 week. Everything seems stable but I wasn't sure if it was loosing potency over the week.

Potatohead · Jul 25, 2018

kswan said:
I was wondering this too. I mix up 4 gallons of saturated solution and use a dosing pump. It lasts about 1 week. Everything seems stable but I wasn't sure if it was loosing potency over the week.

If you keep a lid on it it will not lose much potency. CO2 being introduced to the solution will lower potency so it is actually better to not stir it. Kalk reactors get away with stirring because they are completely sealed, so no CO2 introduction happening.

ncaldwell · Jul 25, 2018

If the the container is not sealed it will start to lose potency but I wouldnt think it would be much over a week. Kalk also developes a kind of crust on the surface so help block against absorbing more co2

kswan · Jul 25, 2018

So why would a kalk reactor (stirrer) be necessary? Is it just to reduce maintenance vs filling mixing a bucket weekly? My assumption is that you can add the kalk and it continues to feed water until the kalk is depleted which would take longer than the same sized bucket?

bubbaque · Jul 25, 2018

kswan said:
So why would a kalk reactor (stirrer) be necessary? Is it just to reduce maintenance vs filling mixing a bucket weekly? My assumption is that you can add the kalk and it continues to feed water until the kalk is depleted which would take longer than the same sized bucket?

A reactor is not needed at all. Randy Holmes Farley has showed a kalk stirrer loses potency more than just putting it in a bucket with a lid on it. If you are using fully saturated kalk, you don't even need to clean the bottom out.

Dennis Cartier · Jul 25, 2018

The benefit of using a stirrer is that you can add more kalk and have a reservoir of undissolved kalk waiting to be dissolved as fresh water is added. At least that is the theory. Now for what happens in practice. I use an Avast K1 kalk stirrer, and I have found (like Randy predicted), that my reactor loses potency overtime. I was using a PH probe to monitor saturation levels, but found that I could have 3" of what looked like undissolved kalk on the bottom of the reactor, being stirred, and yet the water at the top was not fully saturated. When I switched from using PH to EC for monitoring, the fact that I was not fully saturated after a period of time became easier to diagnose. I am not sure why my reactor appears to have undissolved kalk, yet the solution next in line for dosing is not fully saturated. I suspect it may be because I lowered the preset amount of daily dosing and I am not replenishing the solution towards the top of the reactor as fast as usual.

I am planning to switch to the new high PH 2 part once my final ingredient arrives anyway, so why will no longer be relevant.

Dennis

Fishfinder · Jul 25, 2018

Do kalk containers need regular (weekly) cleaning? Or can I keep refilling the same container?

kswan · Jul 25, 2018

I had been curious if adding a small power head inside my bucket to stir for a couple minutes a day would be beneficial for maintaining saturated kalk. Sounds like my current solution does not need to be changed. Thanks for all the information!

Sorry @Fishfinder for hijacking the thread...

sghera64 · Jul 25, 2018

Dennis Cartier said:
The benefit of using a stirrer is that you can add more kalk and have a reservoir of undissolved kalk waiting to be dissolved as fresh water is added. At least that is the theory. Now for what happens in practice. I use an Avast K1 kalk stirrer, and I have found (like Randy predicted), that my reactor loses potency overtime. I was using a PH probe to monitor saturation levels, but found that I could have 3" of what looked like undissolved kalk on the bottom of the reactor, being stirred, and yet the water at the top was not fully saturated. When I switched from using PH to EC for monitoring, the fact that I was not fully saturated after a period of time became easier to diagnose. I am not sure why my reactor appears to have undissolved kalk, yet the solution next in line for dosing is not fully saturated. I suspect it may be because I lowered the preset amount of daily dosing and I am not replenishing the solution towards the top of the reactor as fast as usual.

I am planning to switch to the new high PH 2 part once my final ingredient arrives anyway, so why will no longer be relevant.

Dennis

There is dissolved CO2 in the water being fed to the reactor. That will react with kalk to form insoluble calcium carbonate.

The same thing does happen in bucket/batch setups too. On those cases, once all the CO2 in the initial make up water is reacted, little more is produced.

I too run a kalk reactor. I drain the calcium carbonate off each month and then load a new bolus of fresh kalk. Our kalk reactors see a lot more water pass through them between “make ups “ than the batch/bucket approach. Hence more sediment over time.

bubbaque · Jul 25, 2018

Fishfinder said:
Do kalk containers need regular (weekly) cleaning? Or can I keep refilling the same container?

If you are not dosing fully saturated kalk I believe you should clean it. What settles on the bottom is kalk (along with impurities) that was not able to dissolve because the water is saturated. Adding new water will dissolve more, plus what you measured out. If you are dosing fully saturated then you don't need to clean it as only a certain amount can dissolve before it's saturated.

kswan said:
I had been curious if adding a small power head inside my bucket to stir for a couple minutes a day would be beneficial for maintaining saturated kalk. Sounds like my current solution does not need to be changed. Thanks for all the information!

Sorry @Fishfinder for hijacking the thread...

If your container is not fully sealed, you do not want to mix it again after the initial mix.

Dennis Cartier · Jul 25, 2018

sghera64 said:
There is dissolved CO2 in the water being fed to the reactor. That will react with kalk to form insoluble calcium carbonate.

The same thing does happen in bucket/batch setups too. On those cases, once all the CO2 in the initial make up water is reacted, little more is produced.

I too run a kalk reactor. I drain the calcium carbonate off each month and then load a new bolus of fresh kalk. Our kalk reactors see a lot more water pass through them between “make ups “ than the batch/bucket approach. Hence more sediment over time.

Ah, I was wondering if the layer could be calcium carbonate caused by CO2 in the RODI water. It was the only explanation that I could come up with. Thanks for confirming it.

Dennis

sghera64 · Jul 25, 2018

Dennis Cartier said:
Ah, I was wondering if the layer could be calcium carbonate caused by CO2 in the RODI water. It was the only explanation that I could come up with. Thanks for confirming it.

Dennis

You are welcome. BTW, the “older” the RO/DI water, the more CO2. Fresh DI water should have very little CO2 as the anion resin will bind with the HCO3- and kick out a OH-.