Kalk Reactor Not Working Right

[Scottiemac]

I have an Avast K2 kalk reactor and am using a Kamoer Pro T pump with it. For the first few months this has worked great. I set it to turn on when the pH hits 8.25 and off at 8.30 through the Hydros app. My pH readings were very stable between these lines.

For the last two months it doesn't seem to be absorbing the kalk. One morning I woke up to my sump nearly overflowing (at which point I put a high water level sensor in there) and the pH was still below 8. Then about three hours later my pH had shot up to 8.5. My pH probe was calibrated properly, but even so I replaced it with a new one, which is giving similar readings.

I'm using Avast's house brand of kalk, but also have used one from Saltwater Aquarium which is doing the same thing. I can see the stirrer spinning in the reactor.

The only thing I can think of is that the kalk is not being absorbed in the reactor and the free kalk powder is going into the tank. Eventually it does get absorbed in the tank, which takes a long time in saltwater, and then it's shooting up my pH.

Contacted Avast and they started telling me I shouldn't be running it based on the pH and should be running it based on consumption. That's all well and good, but it doesn't solve the problem.

Has anyone ever seen something like this? In summary, the pump for the reactor can run for hours and not do anything significant to my pH, and then it can shoot up about .5 points.

 

[A_Blind_Reefer]

Seems like an odd way to run kalk. Obviously, you must have a separate ato. Do you know your evaporation limit? Avast isn’t wrong, and one should be dosing based on alkalinity and also not dose more than what evaporates during the day. I would take a step back and figure things out a bit.

 

[Scottiemac]

Seems like an odd way to run kalk. Obviously, you must have a separate ato. Do you know your evaporation limit? Avast isn’t wrong, and one should be dosing based on alkalinity and also not dose more than what evaporates during the day. I would take a step back and figure things out a bit.

Regardless of the odd way to run kalk, the issue remains. pH is not rising when the pump is on like it used to. Nothing has changed external to this setup. I used to be able to watch it rise from 8.25 to 8.3 over about ten-fifteen minutes. Now it can go for hours and only move up a couple hundreds of a point.

 

[A_Blind_Reefer]

Regardless of the odd way to run kalk, the issue remains. pH is not rising when the pump is on like it used to. Nothing has changed external to this setup. I used to be able to watch it rise from 8.25 to 8.3 over about ten-fifteen minutes. Now it can go for hours and only move up a couple hundreds of a point.

Well then. Are you dosing in a high flow area? What happens if you manually take fluid from the reactor and dose it? Is the reactor under/overfilled with kalk? Has the kalk solidified/turned into a heavy sludge at the bottom (but above the stirrer)?

 

[Troylee]

@Sisterlimonpot

 

[Scottiemac]

Well then. Are you dosing in a high flow area? What happens if you manually take fluid from the reactor and dose it? Is the reactor under/overfilled with kalk? Has the kalk solidified/turned into a heavy sludge at the bottom (but above the stirrer)?

It is going into my return section.

I'll check this other stuff out. Thanks for giving me things to look for.

 

[gastone]

Use a hand held, or you hyrdos pH monitor to measure the pH directly from the reactor. Saturated kalkwasser has a pH of roughly 12. I doubt the problem is the reactor itself. They are dead simple.

 

[dwest]

I would check the alkalinity of the effluent. I also would run based off alkalinity consumption not pH. My pH in my tank changes several tenth when family members come and go in my house. Also, pH probes can fluctuate and require calibration and eventually replacement.

 

[A_Blind_Reefer]

It is going into my return section.

I'll check this other stuff out. Thanks for giving me things to look for.

Just trying things out there as a process of elimination. May not be related to anything but might help find what’s changed. I do recommend figuring out your evaporation limit and limiting your dosing based on that. That will help with the overfilling you mentioned and keeps salinity in check.

 

[slythy]

Have you cleaned it? How many cups do you have in there? What size tank do you have? I would assume an overflowing sump on kalk stirrer would cause a huge crash or crazy alk spike.

 

[Scottiemac]

Have you cleaned it? How many cups do you have in there? What size tank do you have? I would assume an overflowing sump on kalk stirrer would cause a huge crash or crazy alk spike.

I've cleaned it several times and put in 3-4 cups of kalk. There's usually a small degree of paste in the bottom, but not enough I'd be worried about it.

 

[Sisterlimonpot]

I have an Avast K2 kalk reactor and am using a Kamoer Pro T pump with it. For the first few months this has worked great. I set it to turn on when the pH hits 8.25 and off at 8.30 through the Hydros app. My pH readings were very stable between these lines.

For the last two months it doesn't seem to be absorbing the kalk. One morning I woke up to my sump nearly overflowing (at which point I put a high water level sensor in there) and the pH was still below 8. Then about three hours later my pH had shot up to 8.5. My pH probe was calibrated properly, but even so I replaced it with a new one, which is giving similar readings.

I'm using Avast's house brand of kalk, but also have used one from Saltwater Aquarium which is doing the same thing. I can see the stirrer spinning in the reactor.

The only thing I can think of is that the kalk is not being absorbed in the reactor and the free kalk powder is going into the tank. Eventually it does get absorbed in the tank, which takes a long time in saltwater, and then it's shooting up my pH.

Contacted Avast and they started telling me I shouldn't be running it based on the pH and should be running it based on consumption. That's all well and good, but it doesn't solve the problem.

Has anyone ever seen something like this? In summary, the pump for the reactor can run for hours and not do anything significant to my pH, and then it can shoot up about .5 points.

Avast marine would know the limitations of their product. I made my own kalk reactor and controller because none of the reactors were designed properly to target pH.

Although it doesn't sound like the hardware is the cause. The suggestion of process of elimination is key. Taking into account that the avast kalk reactor stirrer doesn't do a good job kicking up kalk and creating a cloud doesn't lend well to maintaining full saturation above the stratification line. And when you're requesting a lot of turn over through the reactor the avast isn't the best choice. Something else to consider is the source of the calcium hydroxide, I believe avast recommends vitalcal H which is a pretty pure kalk, but it still leaves behind inert powder that sits at the bottom of the reactor and looks like kalk. Chances are what you see sitting at the bottom needs to be removed and fresh kalk added.

You have to do some math and know how much kalk you added to the reactor and how much effluent the kamoer pump dosed to know when it's time to add more kalk.

The best thing to do is test the pH at the top of the reactor, if it isn't anywhere close to 12.44 then you need to clean out and add kalk more often.

If the pH is up there, then it's time to start looking at how to modify the reactor for your needs and keep kalk in suspension.

 

[lbacha]

I have run an Avast for 6 years and it is really a simple product and it’s doubtful it is the cause of your issue. The key with Kalk is to ensure the reactor PH (measure the clear liquid at the top) stays above 12. If it is then the reactor is working as expected since all it does is slowly agitate the Kalk slurry at the bottom of the reactor so it has better contact with the inflowing water (make sure you have the long hard plastic tube installed that directs the incoming water to the bottom of the reactor). How you push water through the reactor can be done in many ways (as others said I would not base it on PH as you may mess up your salinity and overdose if you do).

I use a dosing pump to add a set amount of water every hour to the reactor which in turn via gravity flows the high PH (kalk saturated) effluent into my sump. I know others just hook it up to their ATO but I get too much fluctuation through the year in evaporation so that doesn’t work for me. The only thing I do control is to shut the Kalk reactor dosing pump off if my trident gives an all reading higher than 8.5 dkh or PH raises higher than 8.4 which in my tank means I’m most likely overdosing Kalk.

Hope this helps, send a picture of your reactor as that may help us diagnose the issue

 

[Sisterlimonpot]

I've cleaned it several times and put in 3-4 cups of kalk. There's usually a small degree of paste in the bottom, but not enough I'd be worried about it.

Keeping in mind that with the avast reactor the amount of "paste" resting at the bottom has to be limited to what the stirrer can dredge through at start up, so that already means that when you're targeting pH you're not going to get sufficient saturation during high demand. Eventually you're replacing the reactor with fresh rodi water that can't fully saturate before leaving the reactor.

That boils down to a better stirrer that creates a continuous cloud of kalk that creates a stratification line that the fresh water can pass through and fully saturate.

 

[lbacha]

Keeping in mind that with the avast reactor the amount of "paste" resting at the bottom has to be limited to what the stirrer can dredge through at start up, so that already means that when you're targeting pH you're not going to get sufficient saturation during high demand. Eventually you're replacing the reactor with fresh rodi water that can't fully saturate before leaving the reactor.

That boils down to a better stirrer that creates a continuous cloud of kalk that creates a stratification line that the fresh water can pass through and fully saturate.

This can be an issue if you use your ATO to top off but is less of a concern with a continuous slow dose through the day. A heavier flow of water into the reactor may actually cloud it up though since the water is directed into the Kalk at the bottom of the avast reactor

 

[Troylee]

This can be an issue if you use your ATO to top off but is less of a concern with a continuous slow dose through the day. A heavier flow of water into the reactor may actually cloud it up though since the water is directed into the Kalk at the bottom of the avast reactor

He’s dosing off ph and nothing else.. the reactor will continue to dose even over the evaporation rate if ph is low. Nothing to do with top off but I know what you’re saying. Sister is dead on with his response as he’s built these and the stand alone controllers for just this purpose.

 

[Sisterlimonpot]

This can be an issue if you use your ATO to top off but is less of a concern with a continuous slow dose through the day. A heavier flow of water into the reactor may actually cloud it up though since the water is directed into the Kalk at the bottom of the avast reactor

I've witnessed that myself, when demand is high the stratification cloud rises inside the reactor. But when you have a effluent pump that can be set to a slower speed, you can create a balance. I personally have my effluent pump set to 60ml/min. But I doubt that would work for an Avast reactor.

 

[Sisterlimonpot]

He’s dosing off ph and nothing else.. the reactor will continue to dose even over the evaporation rate if ph is low. Nothing to do with top off but I know what you’re saying. Sister is dead on with his response as he’s built these and the stand alone controllers for just this purpose.

Yeah, this is the thread for my version of the perfect kalk reactor when targeting pH.

DIY Kalk Controller

For about the last 4 months, I've been tinkering with a controller that will adjust the effluent through a kalk reactor based on input from a pH probe inside the tank. It all started as a conversation about pH being the parameter that we need to be focusing on instead of DKH. At the time I...

www.reef2reef.com

 

[A_Blind_Reefer]

Also curious about your return chamber as that’s where you dose. Is it pretty clean or do you notice a bunch of crusty white substance at the bottom?

Edit. And is the stirrer on 24/7 or do you cycle it? (The bar/rod)

 

[A_Blind_Reefer]

Also @Sisterlimonpot has some great ideas. I just want to clarify that I believe he doses well above the evaporation limit and is able to do so with some custom made gadgetry and super salinity solution to keep salinity in check. Just to clarify this point for those that don’t know. It’s how he can target a specific ph. I don’t know of any one else that is doing this. Targeting a specific ph may require more than a basic kalk reactor on most systems depending on demand, evaporation and such.