Kalk like mud in stirrer, Why?

[vtecintegra]

Using a K1 stirrer with BRS kalk. I've got about a cup in there. My alk and pH took a dive, and I've found the kalk is like thick mud. I can barely pull the stirrer out of the goop. Any idea what's going on? The stirrer is feed RODI.

 

[Pete Luna]

Does the stirrer stir?

 

[vtecintegra]

Yeah, the stirring pad had cut a pathway for itself inside the blob.

 

[Pete Luna]

Thats how mine is. so I beleive thats normal, when I pull the stirrer out it sticks like mud

 

[Randy Holmes-Farley Verified Community Expert]

Can you turn it faster?

 

[vtecintegra]

No, the motor on the stirrer is at a set rpm. Even running 24/7, the stirring paddle just cuts it a little grove into the blob of kalk that forms. I don't see the blob really dissolving, so the water seems like it drops below saturation level.

My alk went from the 9s to low 7, so I said what the heck? Checked the stirrer, and it's pretty much got the same level of kalk in the bottom from last month. Went to pull the stir rod out to make sure the paddle was still spinning, and it was like trying to pull your foot out of mud. The kalk is more like a jelly blob than a fluffy powder. So it looks like the rodi is going in, but the kalk isn't dissolving, doing it's job.

This is no good if the saturation can't be maintained. Maybe I've got too much kalk in there?

 

[Montiman]

I would test the kalk solution in the stirir to see the concentration. You can use an EC meter or pH. It may be working just fine and you might just need to add more kalk to the tank.

If it isn't working then checking the concentration will confirm for you.

 

[vtecintegra]

pH is 11.8 in the stirrer. I'm seeing that 12.4 is considered saturated. So I guess the question is how undersaturated is 11.8?

 

[AquamanE]

Ive got a K2 and try not to put more than 1/2 cup at a time. Keeps it stirred well. Also have a PH probe in that reactor. When full its at around 12.2….I let it go to 11, than just add a bit more to keep PH at 12. Once ph starts dropping quick..like within a week I just take it down and clean the whole think and start again…normally every 3 months or so.
]

 

[Randy Holmes-Farley Verified Community Expert]

pH is 11.8 in the stirrer. I'm seeing that 12.4 is considered saturated. So I guess the question is how undersaturated is 11.8?

About 25% saturated.

 

[vtecintegra]

Thanks guys. I think to reliably run this thing long term, it needs a pH probe.

 

[Randy Holmes-Farley Verified Community Expert]

Thanks guys. I think to reliably run this thing long term, it needs a pH probe.

FWIW, a conductivity meter is a better way to monitor kalkwasser potency.

 

[arking_mark]

Please confirm you are using RODI water...tap/well water can be high in calcium and help create mud.

My other thought looking at the picture is too much Kalk....the BRS stuff is a powder. lots of powder and water = mud.

 

[dwest]

I use a K2. Saturated kalk is clear. If it’s cloudy, then theres some solids too. Your mud looks just like mine.

A pH probe calibrated at 7 and 10 will not likely read the correct pH IME. When I was testing mine, I diluted some solution and used an alkalinity tester to verify it was close to saturation. You can verify this in Randy’s articles but I think saturated kalk near aquarium temperature should be about 100 dKH.

 

[vtecintegra]

Please confirm you are using RODI water...tap/well water can be high in calcium and help create mud.

My other thought looking at the picture is too much Kalk....the BRS stuff is a powder. lots of powder and water = mud.

Yeah, RODI. I pulled the stirrer out and and the kalk seemed to be about twice as thick as pudding.

 

[Spieg]

Can you get it to mix if you use a spoon or something? Almost looks like it never really got mixed well to start with.

 

[vtecintegra]

Yeah, I could mix it with a spoon. I dumped it. I think it was too much in there.

 

[eyesolator]

I am encountering a similar problem with BRS kalk, thick like mud in my reactor. If you look at an old container of BRS kalk, 1 gal 4.5 lbs and compare it by volume to the 4 lbs. of pharma kalk. Pharma kalk is about less than half the volume at a similar weight and is not the fluffy powder we are used to. Allbeit kinda cheesy my two little fishies kalk recator cannot handle the stuff. That reactor always worked flawlessly with any ones kalk but the BRS Pharma is like paste in the bottom. Do not like this stuff at all....

 

[Mywifeisgunnakillme]

probably too much kalk if you're just running saturated kalk. It gets pasty when settling in mass. Personally, just add less kalk and have the reactor stir occassionally or just shake it up once real well when adding kalk and then just dose the water (without stirring again until the water is almost gone). I don't think the saturation level really drops over time (i think you can repeatedly stir to increase saturation but no stirring i don't think drops it--randy could chime there)... Really just having a consistent dose, whatever the saturation level is, i think is what you want.

i run kalk as a slurry and just stir it up automatically a minute or so before dosing, many times a day. That has held alk very stable; there are lots of ways to run kalk!

 

[eyesolator]

probably too much kalk if you're just running saturated kalk. It gets pasty when settling in mass. Personally, just add less kalk and have the reactor stir occassionally or just shake it up once real well when adding kalk and then just dose the water (without stirring again until the water is almost gone). I don't think the saturation level really drops over time (i think you can repeatedly stir to increase saturation but no stirring i don't think drops it--randy could chime there)... Really just having a consistent dose, whatever the saturation level is, i think is what you want.

i run kalk as a slurry and just stir it up automatically a minute or so before dosing, many times a day. That has held alk very stable; there are lots of ways to run kalk!

Too little kalk and it does not form a cloud at the bottom/not mixing. I know how the typical sludge at the bottom of a reactor is and had never posed a problem with normal kalk.
The way a TLF reactor works in not by a constant drip and stir once in a while. Water is pumped into the reactor and down a tube near the bottom and on the bottom of the tube is a device that spins when water is pumped through it mixing the kalk. The excess water that is pumped in overflows at the top of the reactor and into the tank. Mine is set up to run every 25 minutes so it's not as though the a great deal of time has lapsed between stirs to allow the kalk to turn to paste.