How often should I mix my Kalk in the reactor?

Rst

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I have been using an apex pH module & probe to try and determine when my Kalk reactor’s was becoming un-saturated and would need refilling. According the the advice given, a better indicator to use would be my apex conductivity probe. As an experiment, I have now replaced the pH probe with the apex conductivity probe and in addition, guessing I should change the “Range” setting in the salinity module settings to “High (0-85mS/cm)”

After cleaning out the reactor and adding fresh RO water and 2 cups of Kalk powder, then inserting my apex conductivity probe, the reading now shows 19.8 mS/cm. According to this thread, it seems I should be seeing more like 10 mS/cm??

Can anybody help me with an idea as how far to gauge before I should be upping my Kalk reactor’s concentration with the help of the new readings?
 
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Randy Holmes-Farley

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I have been using an apex pH module & probe to try and determine when my Kalk reactor’s was becoming un-saturated and would need refilling. According the the advice given, a better indicator to use would be my apex conductivity probe. As an experiment, I have now replaced the pH probe with the apex conductivity probe and in addition, guessing I should change the “Range” setting in the salinity module settings to “High (0-85mS/cm)”

After cleaning out the reactor and adding fresh RO water and 2 cups of Kalk powder, then inserting my apex conductivity probe, the reading now shows 19.8 mS/cm. According to this thread, it seems I should be seeing more like 10 mS/cm??

Can anybody help me with an idea as how far to gauge before I should be upping my Kalk reactor’s concentration with the help of the new readings?

The conductivity is certainly not 19.8 mS/cm if it is just fresh water and calcium hydroxide.

What are the other ranges possible to set it to?
 

Rst

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There are 2 additional options: MED (0-8.5 mS/cm) or LOW (0-850 uS/cm).

There is a little more info to share. Since I first made this change yesterday around 11am, I mistakenly reported the reading as 19.8, but when checking the apex graph for conductivity this morning, I discovered that it actually showed the following: Yesterday: 12pm 11.9; 6pm 10.9; 8pm 10.7; 11:45pm 10.2; and then sudden jump immediately thereafter to: 12am 16.9; 6am 15.8; 8am 15.3; 9am 15.2

As you can see, there was a surprising sudden jump around midnight. I haven't calibrated this probe in a while so perhaps the probe readings are misleading. Do you think I should still be able to make use when utilizing this probe in my KALK reactor? So far, Is this experiment as a total failure?

Thank you Randy,
Ron
 
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ZombieEngineer

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There are 2 additional options: MED (0-8.5 mS/cm) or LOW (0-850 uS/cm).

There is a little more info to share. Since I first made this change yesterday around 11am, I mistakenly reported the reading as 19.8, but when checking the apex graph for conductivity this morning, I discovered that it actually showed the following: Yesterday: 12pm 11.9; 6pm 10.9; 8pm 10.7; 11:45pm 10.2; and then sudden jump immediately thereafter to: 12am 16.9; 6am 15.8; 8am 15.3; 9am 15.2

As you can see, there was a surprising sudden jump around midnight. I haven't calibrated this probe in a while so perhaps the probe readings are misleading. Do you think I should still be able to make use when utilizing this probe in my KALK reactor? So far, Is this experiment as a total failure?

Thank you Randy,
Ron
You need to let it sit for a while and work the bubbles out of the probe. Because this is the low end of the range and you haven't calibrated at the new range, the actual raw numbers are not important. What is important is the pattern you see after stirring and how that changes as the kalk gets exhausted.

Just let it run until your kalk is exhausted and see how the conductivity pattern changes over time.
 

Rst

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@ZombieEngineer thanks for weighing in. I am very much hoping that using this probe, instead of the pH probe, will make the determination of when to reset the KALK in the reactor more apparent.

I am a totally new Kalk reactor user. In my case, I am using the Avast Marine K2 Kalk stirrer where the stirrer is running slowly 24hour/day and a very low drip rate slightly lower than my daily evaporation rate. I noticed that you suggested that I should make my determinations "after stirring". Would you recommend that I switch to only periodic stirring as a better approach?

Also, do you have any suggestions as to what pattern of readings might indicate that it is close to exhaustion?

Hope you don't mind my questions, just trying to get a better gripe on how to utilize kalk more efficiently.
 

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@ZombieEngineer thanks for weighing in. I am very much hoping that using this probe, instead of the pH probe, will make the determination of when to reset the KALK in the reactor more apparent.

I am a totally new Kalk reactor user. In my case, I am using the Avast Marine K2 Kalk stirrer where the stirrer is running slowly 24hour/day and a very low drip rate slightly lower than my daily evaporation rate. I noticed that you suggested that I should make my determinations "after stirring". Would you recommend that I switch to only periodic stirring as a better approach?

Also, do you have any suggestions as to what pattern of readings might indicate that it is close to exhaustion?

Hope you don't mind my questions, just trying to get a better gripe on how to utilize kalk more efficiently.
The full proof method to tell when it is exhausted is to measure the alkalinity. If your test set uses 10ml sample, mix 1ml kalk with 9ml rodi. Fully saturated should read 10dKH. When it starts reading like 70-80% of that, you know it's starting to exhaust and when it reads less than 5, it's less than half saturation and definitely exhausted.

I would just test it every couple days and get a pattern of how they readings relate. Then if say normal reads 15 and when dKH drops to 5 (actually 50dKH, just diluted to 5) the reading shows 7, then set your alarm to refill it when < 7
 
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Rst

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The full proof method to tell when it is exhausted is to measure the alkalinity. If your test set uses 10ml sample, mix 1ml kalk with 9ml rodi. Fully saturated should read 10dKH. When it starts reading like 70-80% of that, you know it's starting to exhaust and when it reads less than 5, it's less than half saturation and definitely exhausted.

I would just test it every couple days and get a pattern of how they readings relate. Then if say normal reads 15 and when dKH drops to 5 (actually 50dKH, just diluted to 5) the reading shows 7, then set your alarm to refill it when < 7
Great info, this method of using the Kalk alkalinity as the gauge, I don’t ever remember reading this before. I am going to give this a try and see how it relates and compare this result to say the results from my conductivity probe. Thanks
 

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Great info, this method of using the Kalk alkalinity as the gauge, I don’t ever remember reading this before. I am going to give this a try and see how it relates and compare this result to say the results from my conductivity probe. Thanks

One issue is it needs to be clear, without particulates. Conductivity is foolproof if measured accurately because particulates do not interfere.

Saturated clear kalkwasser at 25 deg C has an alkalinity of 40.8 meq/L (114 dkH) and a calcium concentration of 808 ppm. The 1/10 dilution puts it at 11.4 dKH.

Any particulates in it will give it a false high dissolved alk reading.
 

Rst

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One issue is it needs to be clear, without particulates. Conductivity is foolproof if measured accurately because particulates do not interfere.

Saturated clear kalkwasser at 25 deg C has an alkalinity of 40.8 meq/L (114 dkH) and a calcium concentration of 808 ppm. The 1/10 dilution puts it at 11.4 dKH.

Any particulates in it will give it a false high dissolved alk reading.

Really interesting info. I love science! (even through my old brain struggles with it all the time :grinning-face-with-big-eyes: ) So far, I have only made 2 measurements of the KALK in my reactor both 1/10dilution result & the conductivity reported by my apex conductivity probe. At 4pm yesterday the 1/10th reading was 15.2dkh & the apex reading was 14.0uS/cm. Now at 8am today the 1/10th reading already dropped to 10.6dkh & the apex reading at the same time was 12.4uS/cm. Seems to me that there is a reasonable correlation so far and that my KALK solution is exhausting very very quickly.

I wish there some way of slowing down the lightening speed of the Kalk dilution before I need to replenish the calcium Hydroxide. I am finding that only after a half a dozen of 1 cup refills of the calcium Hydroxide (after it's exhausted), it leaves a ton of sludge that is a real pain to clean out of the reactor. Lifting the reactor when filled with 3 gals of solution & full of sludge to a sink located downstairs is really no fun.

Randy, would changing my constant continuous 24 hours/day stirring in the reactor to only stirring once every 6 hours make any difference in maintenance of the kalk reactor? Is there a better way?
 
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I had the Avast one before, and that one is made to run 24/7 very slowly. The Ice Cap one that I'm using mixes very fast and turns the entire mixing chamber milk white when it's running. For that reason it can't run 24/7 and I need to not be dosing when the stir is running.

I had the same issue with the Avast, and I extended the input down into the Kalk slurry, and bent the stir bar to help it mix up a little bit better to help with that. It helped a little bit, but I also added 1/4 cup weekly, and cleaned it monthly to make sure there was no accumulation.

To be honest I haven't been happy with any Kalk reactor yet. The Ice Cap one is better in one way because it mixes so much better, but it has the issue that it can't handle more than about 1/2 cup of Kalk or the magnetic pill either sticks in place, or it falls off to the side making it not work at all. So I'm still adding 1/4 cup per week with this one. It does suffer much less buildup though it seems.

Whiskey
 
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Rst

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I had the Avast one before, and that one is made to run 24/7 very slowly. The Ice Cap one that I'm using mixes very fast and turns the entire mixing chamber milk white when it's running. For that reason it can't run 24/7 and I need to not be dosing when the stir is running.

I had the same issue with the Avast, and I extended the input down into the Kalk slurry, and bent the stir bar to help it mix up a little bit better to help with that. It helped a little bit, but I also added 1/4 cup weekly, and cleaned it monthly to make sure there was no accumulation.

To be honest I haven't been happy with any Kalk reactor yet. The Ice Cap one is better in one way because it mixes so much better, but it has the issue that it can't handle more than about 1/2 cup of Kalk or the magnetic pill either sticks in place, or it falls off to the side making it not work at all. So I'm still adding 1/4 cup per week with this one. It does suffer much less buildup though it seems.

Whiskey
I appreciate your report. According to Avast's suggested maintenance, I need to add 1.25 cups every 2 weeks based on my display tank's evaporation rate of 1.5 gallons/day. In reality, my kalk drops to 1/2 strength in only 3 or 4 days. Topping up the calcium hydroxide is not the problem really. Its just that needing to completely empty the 3 gals of sludge & solution down to the basement when weighing over 30 lbs every couple of weeks becomes back breaking. Since the sludge & solution is not something that you can dispose of just anywhere, you must carry it somewhere to dispose of it safely.
There has got to be a better way.
 
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I appreciate your report. According to Avast's suggested maintenance, I need to add 1.25 cups every 2 weeks based on my display tank's evaporation rate of 1.5 gallons/day. In reality, my kalk drops to 1/2 strength in only 3 or 4 days. Topping up the calcium hydroxide is not the problem really. Its just that needing to completely empty the 3 gals of sludge & solution down to the basement when weighing over 30 lbs every couple of weeks becomes back breaking. Since the sludge & solution is not something that you can dispose of just anywhere, you must carry it somewhere to dispose of it safely.
There has got to be a better way.

If I were you, I would stop using this for ATO. I've had that bite me in the butt too many times. I would put it on a dosing pump and choose some amount less than Evap to dose, then your ATO makes up for the rest. I was going with 1 gallon per day on a 200 gallon system, but PH became an issue when I was out of the house. I'm down to about 3/4 gallon per day now.

Regarding Avast's recommendations, I don't hate it, but I think it's adding too much at once, too infrequently. The Avast reactor never really kicks everything up into the water colum and fully saturates it. I think allot of your Kalk is getting trapped at the bottom and never saturating the water. If you can slam that stir bar all the way down, and add 1/4 cup every 3-4 days I think the mix will be much more consistent, and you may find that less sludge collects. Another idea is to lift up the lid and really mix that up heavily every few days so that all the sludge comes up into the water for a brief time.

The other issue with ATO fed is that sometimes it's too much, too fast, all at once and the new water never gets a chance to saturate.

Whiskey
 
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So many ppl say kalk stirrer are great. So many say the opposite. Seems to be 50/50 but I'd like to know what other variable factor these outcomes. For example, is it the smaller demanding tanks that seems to have longer time between servicing. I honestly feel I will one of those that give it a negative experience..Mainly bc I evaporates 5 gallons daily and will be overfilling it to compensate for 2 weeks
 

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If I were you, I would stop using this for ATO. I've had that bite me in the butt too many times. I would put it on a dosing pump and choose some amount less than Evap to dose, then your ATO makes up for the rest. I was going with 1 gallon per day on a 200 gallon system, but PH became an issue when I was out of the house. I'm down to about 3/4 gallon per day now.
Actually I do not use the kalk reactor for ATO, but instead only as a pH booster. I feed the reactor from my RO reserve tank and then use a dosing pump to slowly draw the kalkwasser solution into my sump. I set the doser to run 24 hrs/day at a rate just below my evaporation rate. The majority of my calcium and alkalinity needs comes from my calcium reactor.
Regarding Avast's recommendations, I don't hate it, but I think it's adding too much at once, too infrequently. The Avast reactor never really kicks everything up into the water colum and fully saturates it. I think allot of your Kalk is getting trapped at the bottom and never saturating the water. If you can slam that stir bar all the way down, and add 1/4 cup every 3-4 days I think the mix will be much more consistent, and you may find that less sludge collects. Another idea is to lift up the lid and really mix that up heavily every few days so that all the sludge comes up into the water for a brief time.
yes I also found that the stirrer may not be doing a great job. I will try your suggestions and see if this helps with reducing my frequent need to refill and clean out the kalkwasser reactor.
thanks
The other issue with ATO fed is that sometimes it's too much, too fast, all at once and the new water never gets a chance to saturate.

Whiskey
 

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I recently setup Kalk on this new tank. Busted out my 3 yr old ESV Kalk. Mixed it up put it in my reservoir and hadn’t touched it. Had it running for about a week and figured I’d test the pH just to see how low it was. To my surprise it came in at 12.3-12.4. I was pretty shocked.
 
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So many ppl say kalk stirrer are great. So many say the opposite. Seems to be 50/50 but I'd like to know what other variable factor these outcomes. For example, is it the smaller demanding tanks that seems to have longer time between servicing. I honestly feel I will one of those that give it a negative experience..Mainly bc I evaporates 5 gallons daily and will be overfilling it to compensate for 2 weeks

I like to mix mine up and put it in a reservoir and dose with my GHL. I don’t touch it afterwards or open the lid. Mine lasts about 1 week +/- depending on demand and reservoir size. When I test it, it’s 12.3-12.4. I’m fixing to move to a 5/G reservoir I believe and do it the same way.
 

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Once I hit 1,000 mL’s and above. The 5/G is coming in and this will go back in the garage. :)

F9937F6D-B811-4B82-8961-913269C99024.jpeg
 

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