My brainstorming idea on avoiding the kalkwasser evaporation limit.

[Miami Reef]

This is just an idea I had. All theoretical!


Kalkwasser is inexpensive, convenient to dose, all in one, not subject to skewing salt composition with sodium chloride, and has the highest pH boost possible (hydroxide).


The downsides, in my opinion, are these:


1) Can have impurities (this is why dosing in a kalk stirrer isn’t a perfect solution, since the natural precipitation can make kalkwasser “self-purifying.” (Randy Holmes-Farely, What Your Grandmother Never Told You About Lime)



2) It is not very water-soluble; you often need to dose gallons DAILY of a fully saturated solution to maintain large, high-alk-demand tanks. It’s a pain to mix up large volumes of limewater consistently and isn’t space efficient.



3) High-demand tanks are often limited by the evaporation limit, meaning you can’t dose enough alkalinity and calcium via kalkwasser because the water level will get too high. The amount of linewater solution exceeds the water that is evaporated.



4) Some people go to great lengths to increase their evaporation, such as using fans or aggressively agitating the surface, but it can increase the home humidity and still might not be enough in very high-demand tanks.




I’ve been brainstorming for fun. This is what I came up with. This is all theoretical!!



Step 1: We would need kalkwasser free of impurities that can directly dosed into the tank.



Step 2: We need an instrument that can reliably and accurately dose powdered kalkwasser. Akin to an automatic fish pellet feeder (like Ehime) that dispenses powdered kalkwasser. It should be programmed multiple times a day. (Ideally once every hour, IMO).


This method would theoretically work well in large, high flow tanks with chronically low pH. It would be dosed upstream, furthest away from the return pumps in the sump in a high-flow area.




Limitations:



1) Do precise, powdered dosing systems exist?

2) Would humidity cause the powder to clog the dosing machine?

3) Is there calcium hydroxide that doesn’t have metal impurities that can be directly dosed into the tank?

4) I’m not sure if powdered dosing systems have fail-safe options.

5) If you don’t have a large sump and high flow, then it would not be an ideal method to consider.

6) CO2 will rapidly degrade the Ca(OH)2. The dosing system would somehow need to be air-tight.





This is just a fun idea. I am not doing this nor do I plan to FYI. Just brainstorming. I don’t even use kalkwasser because of the limitations above.

@Randy Holmes-Farley

 

[robinm]

Why not build a kalk stirrer that takes input water from the sump rather than rodi? There must be a reason why it isn't done impurities aside.

 

[Stang67]

Why not build a kalk stirrer that takes input water from the sump rather than rodi? There must be a reason why it isn't done impurities aside.

A recirculation method of dosing rather than from the ato. Yes I like that idea.

 

[Orito]

Kalk don't dissolve in saltwater and will precipitate your magnesium

 

[robinm]

Knew there had to be a reason, that blows up the OPs idea.

 

[Miami Reef]

How soluble is calcium hydroxide in seawater compared to freshwater?

This thread is just me bouncing off ideas. I’m just curious. I’m not switching to kalkwasser nor am I encouraging this idea. The low solubility of kalkwasser is very interesting to me.

 

[Randy Holmes-Farley]

Why not build a kalk stirrer that takes input water from the sump rather than rodi? There must be a reason why it isn't done impurities aside.

As folks note, there will be precipitation of magnesium hydroxide and calcium carbonate inside of it.

 

[Randy Holmes-Farley]

This is just an idea I had. All theoretical!


Kalkwasser is inexpensive, convenient to dose, all in one, not subject to skewing salt composition with sodium chloride, and has the highest pH boost possible (hydroxide).


The downsides, in my opinion, are these:


1) Can have impurities (this is why dosing in a kalk stirrer isn’t a perfect solution, since the natural precipitation can make kalkwasser “self-purifying.” (Randy Holmes-Farely, What Your Grandmother Never Told You About Lime)



2) It is not very water-soluble; you often need to dose gallons DAILY of a fully saturated solution to maintain large, high-alk-demand tanks. It’s a pain to mix up large volumes of limewater consistently and isn’t space efficient.



3) High-demand tanks are often limited by the evaporation limit, meaning you can’t dose enough alkalinity and calcium via kalkwasser because the water level will get too high. The amount of linewater solution exceeds the water that is evaporated.



4) Some people go to great lengths to increase their evaporation, such as using fans or aggressively agitating the surface, but it can increase the home humidity and still might not be enough in very high-demand tanks.




I’ve been brainstorming for fun. This is what I came up with. This is all theoretical!!



Step 1: We would need kalkwasser free of impurities that can directly dosed into the tank.



Step 2: We need an instrument that can reliably and accurately dose powdered kalkwasser. Akin to an automatic fish pellet feeder (like Ehime) that dispenses powdered kalkwasser. It should be programmed multiple times a day. (Ideally once every hour, IMO).


This method would theoretically work well in large, high flow tanks with chronically low pH. It would be dosed upstream, furthest away from the return pumps in the sump in a high-flow area.




Limitations:



1) Do precise, powdered dosing systems exist?

2) Would humidity cause the powder to clog the dosing machine?

3) Is there calcium hydroxide that doesn’t have metal impurities that can be directly dosed into the tank?

4) I’m not sure if powdered dosing systems have fail-safe options.

5) If you don’t have a large sump and high flow, then it would not be an ideal method to consider.

6) CO2 will rapidly degrade the Ca(OH)2. The dosing system would somehow need to be air-tight.





This is just a fun idea. I am not doing this nor do I plan to FYI. Just brainstorming. I don’t even use kalkwasser because of the limitations above.

@Randy Holmes-Farley

If you can reasonably meter in solid powder the concerns become getting it dissolved fast enough to avoid local precipitation of calcium carbonate near or onto the dissolving particle, and avoiding the particles getting to any delicate organisms. I expect these are solvable problems.

A few folks have used a slurry of particles in fresh water. That can work, but has the issues mentioned above plus the difficulty of controlling how much solid is in a given amount of water.

 

[Dan_P]

This is just an idea I had. All theoretical!


Kalkwasser is inexpensive, convenient to dose, all in one, not subject to skewing salt composition with sodium chloride, and has the highest pH boost possible (hydroxide).


The downsides, in my opinion, are these:


1) Can have impurities (this is why dosing in a kalk stirrer isn’t a perfect solution, since the natural precipitation can make kalkwasser “self-purifying.” (Randy Holmes-Farely, What Your Grandmother Never Told You About Lime)



2) It is not very water-soluble; you often need to dose gallons DAILY of a fully saturated solution to maintain large, high-alk-demand tanks. It’s a pain to mix up large volumes of limewater consistently and isn’t space efficient.



3) High-demand tanks are often limited by the evaporation limit, meaning you can’t dose enough alkalinity and calcium via kalkwasser because the water level will get too high. The amount of linewater solution exceeds the water that is evaporated.



4) Some people go to great lengths to increase their evaporation, such as using fans or aggressively agitating the surface, but it can increase the home humidity and still might not be enough in very high-demand tanks.




I’ve been brainstorming for fun. This is what I came up with. This is all theoretical!!



Step 1: We would need kalkwasser free of impurities that can directly dosed into the tank.



Step 2: We need an instrument that can reliably and accurately dose powdered kalkwasser. Akin to an automatic fish pellet feeder (like Ehime) that dispenses powdered kalkwasser. It should be programmed multiple times a day. (Ideally once every hour, IMO).


This method would theoretically work well in large, high flow tanks with chronically low pH. It would be dosed upstream, furthest away from the return pumps in the sump in a high-flow area.




Limitations:



1) Do precise, powdered dosing systems exist?

2) Would humidity cause the powder to clog the dosing machine?

3) Is there calcium hydroxide that doesn’t have metal impurities that can be directly dosed into the tank?

4) I’m not sure if powdered dosing systems have fail-safe options.

5) If you don’t have a large sump and high flow, then it would not be an ideal method to consider.

6) CO2 will rapidly degrade the Ca(OH)2. The dosing system would somehow need to be air-tight.





This is just a fun idea. I am not doing this nor do I plan to FYI. Just brainstorming. I don’t even use kalkwasser because of the limitations above.

@Randy Holmes-Farley

It seems the only obstacle is obtaining small scale equipment that is reliable and affordable to add the powder to rapidly stirred aquarium water. A tiny screw feeder might be the engineering solution for controlled powder dosing. Not sure how to deal with rat holing the kalkwasser powder. The point of mixing needs to be extremely turbulent. This might be accomplished with a small reactor consisting of a powerhead and baffles.

 

[KStatefan]

It seems the only obstacle is obtaining small scale equipment that is reliable and affordable to add the powder to rapidly stirred aquarium water.

I think that is a pretty big obstacle to get reliable and affordable. I started to look into it a few years ago but quickly decided it was not going to be worth it when there are many other otions to raise alk. I was heading down the direction of a metered slide that you varied how often the slide was operated.

@Sisterlimonpot has a DIY system to increase to get him above the evaporation limit by using an auto water change system that replace what is pulled out with a higher salinity replacement.

 

[Dan_P]

I think that is a pretty big obstacle to get reliable and affordable. I started to look into it a few years ago but quickly decided it was not going to be worth it when there are many other otions to raise alk. I was heading down the direction of a metered slide that you varied how often the slide was operated.

@Sisterlimonpot has a DIY system to increase to get him above the evaporation limit by using an auto water change system that replace what is pulled out with a higher salinity replacement.

With 3D printing being more available these days, we might be a tiny bit closer to building a powder addition system that works. I don’t know about the affordable angle. I agree that there are some clever solutions to this challenge already.

 

[reef_ranch]

Kalk slurry is the simplest method. I've been using Rob B's method for a couple of years now. Works great. No issues with impurities using high quality kalk.

 

[Malcontent]

Take a look at gunpowder tricklers to see what's possible. We could probably accept less accuracy to lower cost since those aim to dose single grains of gunpowder (~65 mg each).

 

[Slocke]

Vinegar and other acids would increase solubility however I found that despite Kaltwasser being highly basic that my tank water lost pH when trying to increase solubility with vinegar.

As a side note I think another con of kalkwasser is its lack of magnesium. Would love to have a product that had the magnesium already mixed in at a good ratio.

 

[Sisterlimonpot]

Just to be clear, is this shaping into thought experiment to figure out a way to introduce dry calcium hydroxide powder to tank water in order to maintain calcium carbonate?

EDIT: If so then the biggest challenge for an automation process would be keeping the powder dry.

I've been experimenting with an automated means to refill my kalk reactor so that I don't even have to mess with that, and the one obstacle I can't overcome is turning the dry powder into wet paste during at the introduction point.

 

[Miami Reef]

Thank you everyone for the kind responses!

As a side note I think another con of kalkwasser is its lack of magnesium. Would love to have a product that had the magnesium already mixed in at a good ratio.

All For Reef is the answer you are looking for! It has magnesium inside. The only difference is that it doesn’t have the pH boost and is a little more pricier.

 

[Slocke]

Thank you everyone for the kind responses!


All For Reef is the answer you are looking for! It has magnesium inside. The only difference is that it doesn’t have the pH boost and is a little more pricier.

I have switched back to AFR. I’m just saying it would be a good product if it were cheaper then AFR

 

[Miami Reef]

If you can reasonably meter in solid powder the concerns become getting it dissolved fast enough to avoid local precipitation of calcium carbonate near or onto the dissolving particle, and avoiding the particles getting to any delicate organisms. I expect these are solvable problems.

The point of mixing needs to be extremely turbulent. This might be accomplished with a small reactor consisting of a powerhead and baffles.

Thanks guys! I didn’t expect my logic to actually work. That’s pretty interesting.

My sump has a lot of baffles and is extremely high flow, especially in the area where the overflow pipes first enter the sump. I understand that this is not the experience with everyone’s setup.

Another fun idea I had was turning kalkwasser powder into those extended release tablets or a pelleted form. Perhaps a dosing system would have an easier and accurate time at dispensing pills and pellets than powder. This would also protect the kalkwasser from CO2 and will prevent the puff cloud when it falls into the water.

Obviously this might increase the precipitation if the pills/tablets don’t dissolve fast enough.

Again, I’m not actually going to use this method. I just think it’s fun to brainstorm ideas and solutions.

 

[Lousybreed]

This is just an idea I had. All theoretical!


Kalkwasser is inexpensive, convenient to dose, all in one, not subject to skewing salt composition with sodium chloride, and has the highest pH boost possible (hydroxide).


The downsides, in my opinion, are these:


1) Can have impurities (this is why dosing in a kalk stirrer isn’t a perfect solution, since the natural precipitation can make kalkwasser “self-purifying.” (Randy Holmes-Farely, What Your Grandmother Never Told You About Lime)



2) It is not very water-soluble; you often need to dose gallons DAILY of a fully saturated solution to maintain large, high-alk-demand tanks. It’s a pain to mix up large volumes of limewater consistently and isn’t space efficient.



3) High-demand tanks are often limited by the evaporation limit, meaning you can’t dose enough alkalinity and calcium via kalkwasser because the water level will get too high. The amount of linewater solution exceeds the water that is evaporated.



4) Some people go to great lengths to increase their evaporation, such as using fans or aggressively agitating the surface, but it can increase the home humidity and still might not be enough in very high-demand tanks.




I’ve been brainstorming for fun. This is what I came up with. This is all theoretical!!



Step 1: We would need kalkwasser free of impurities that can directly dosed into the tank.



Step 2: We need an instrument that can reliably and accurately dose powdered kalkwasser. Akin to an automatic fish pellet feeder (like Ehime) that dispenses powdered kalkwasser. It should be programmed multiple times a day. (Ideally once every hour, IMO).


This method would theoretically work well in large, high flow tanks with chronically low pH. It would be dosed upstream, furthest away from the return pumps in the sump in a high-flow area.




Limitations:



1) Do precise, powdered dosing systems exist?

2) Would humidity cause the powder to clog the dosing machine?

3) Is there calcium hydroxide that doesn’t have metal impurities that can be directly dosed into the tank?

4) I’m not sure if powdered dosing systems have fail-safe options.

5) If you don’t have a large sump and high flow, then it would not be an ideal method to consider.

6) CO2 will rapidly degrade the Ca(OH)2. The dosing system would somehow need to be air-tight.





This is just a fun idea. I am not doing this nor do I plan to FYI. Just brainstorming. I don’t even use kalkwasser because of the limitations above.

@Randy Holmes-Farley

Dude I have been dosing Kalk Slurry for years. It’s all on my IG page. Works just fine. Buy captiv8 kalk and you will be successful. My IG is quanta_lights and I have my kalk slurry presentations pinned for ease of access.

 

[Lousybreed]

Kalk don't dissolve in saltwater and will precipitate your magnesium

False. My mag levels are just fine. Been dosing kalk slurry since 2021.