Kalk stirrer thoughts.

[Joe Batt]

Provided there is enough kalkwasser in a stirrer, is the liquid in the kalk stirrer maintained at 100% saturation?

If it is, does it matter the amount of kalkwasser you add to the stirrer? The slurry just reducing slowly as fresh RODI is added via the ATO until you need to add more Kalkwasser?

 

[Reeferdood]

I would say that it is close to 100% saturation, I have used a stirrer on and off for years and they are awesome. The slurry will loose potency over time depending on your evaporation rate, assuming you are using it via an ATO. What I do is every other time it is time to refill it, I'll clean it out and replace the old slurry.
The old buildup at the bottom gets thick and I feel it will wear down the motor faster if you don't keep it clean. That is my method, I am sure there are others that work equally as well too.

 

[Joe Batt]

Thanks for that. So from my understanding, it doesn't matter the amount added to the stirrer (within reason). How do you adjust the amount that is dosed daily, since it is dependent on the evaporation rate of your tank. Wouldnt this in theory be too much or too little?

 

[Reeferdood]

That is precisely how they work if being used via an ATO. For some, myself included; I supplement the kalkwasser with a 2 part since my evaporation rate is not enough to maintain calcium and alkalinity alone. If you have too much evaporation and you fear overdosing then you could work some magic with your plumbing and add a tee with a small valve to dose less Kalk and a little fresh RO water at the same time... Almost everything in reefing requires some sort of modification since every system in different...
Hope this helps.

 

[Joe Batt]

Thanks for the info

 

[Reeferdood]

My pleasure, I hope it works out for you.

 

[Dennis Cartier]

I use this setup currently on my frag tank (Kalk with 2 part). To keep levels stable, I use a timer to dose a fixed amount of kalk through a peristaltic pump over a 24 hour period and use my normal ATO to make up the shortfall between evaporation and the amount of kalk being added. As long as your added kalk remains lower than the evaporation amount, this works fairly well.

The other factor in keeping alk stable when using kalk is making sure that the kalk you are adding is fully saturated. I have found that my Avast K1 reactor starts to lose potency after a couple of days. At first I was thinking it was the standing water at the top of the reactor that was absorbing CO2 (the reactor is not pressurized), but another reefer alerted me to the fact that the RODI water also contains CO2, so it reduces the saturation of the kalk over time. I really started to zero in on the saturation level when I switched to using a EC probe rather than PH for measuring saturation. Fully saturated kalk is about 10.3 ms/s according to Randy.

I had planned on experimenting with a sealed non stirred Nilsen style reactor using mason jars and a couple of 1/4" bulkheads, but when I found out that the CO2 carried with the RODI also impacts the saturation, I am no longer as eager to go to this trouble. I still may try this with some smaller quarantine tanks. I found that the HM Digital TDS meters could be used to monitor the saturation of the kalk exiting the reactor. Fully saturated Kalk reads ~ 6400 ppm (about 640 on the display along with 10x flag).

Dennis

 

[chema]

I use this setup currently on my frag tank (Kalk with 2 part). To keep levels stable, I use a timer to dose a fixed amount of kalk through a peristaltic pump over a 24 hour period and use my normal ATO to make up the shortfall between evaporation and the amount of kalk being added. As long as your added kalk remains lower than the evaporation amount, this works fairly well.

The other factor in keeping alk stable when using kalk is making sure that the kalk you are adding is fully saturated. I have found that my Avast K1 reactor starts to lose potency after a couple of days. At first I was thinking it was the standing water at the top of the reactor that was absorbing CO2 (the reactor is not pressurized), but another reefer alerted me to the fact that the RODI water also contains CO2, so it reduces the saturation of the kalk over time. I really started to zero in on the saturation level when I switched to using a EC probe rather than PH for measuring saturation. Fully saturated kalk is about 10.3 ms/s according to Randy.

I had planned on experimenting with a sealed non stirred Nilsen style reactor using mason jars and a couple of 1/4" bulkheads, but when I found out that the CO2 carried with the RODI also impacts the saturation, I am no longer as eager to go to this trouble. I still may try this with some smaller quarantine tanks. I found that the HM Digital TDS meters could be used to monitor the saturation of the kalk exiting the reactor. Fully saturated Kalk reads ~ 6400 ppm (about 640 on the display along with 10x flag).

Dennis

Thanks for a very interesting posting. Which is the HM model you use to monitor the saturation of talk?

 

[Dennis Cartier]

Thanks for a very interesting posting. Which is the HM model you use to monitor the saturation of talk?

I tested this on the DM1 dual TDS meter. I never ended up using it unfortunately. Though I still consider it a viable means of tracking the saturation level. I actually no longer Kalk at all on this tank. I added an Alkatronic and found (once I had constant alk measuring), that I could get better stability by taking kalk out of the mix. Also when first setting up the Alkatronic, having only 1 source of alkalinity made it easier for the alk monitor to modulate the alk level.

If I were to resume Kalk, I would definitely use EC/TDS to monitor its strength. I have a larger Kalk stirrer on hand already that I had planned to use in my 500G DT I am building, but am undecided if I will go ahead with it or use another means of adding Alk/Ca. I am most likely going to go with a CalRx.

Dennis