When do you add more calcium hydroxide to Kalk stirrer?

[ScottB]

Do you mind sharing how you setup your programming? I am planning to try adding a kalk stirrer as well to try to help stabilize pH.

I use 2-part currently. I’ve been kicking around several ideas on how to approach programming a DOS to push RO through the kalk stirrer.

Like you, will be mainly at night. Just curious how you programmed yours.

I use one of the heads of my APEX DOS. It pulls water from my RODI water storage tank and pushes it into my Reef Octo stirrer. This overflows the stirrer and it is a gravity feed from there into the sump return section.

The programming is super easy and very flexible, allowing me to dose at different rates over different periods of time. I highly recommend. My range is now 8.35 to 8.46 peak.

 

[Cjeippert]

I used to just mix up kalk in my ato then cover it with saran wrap. Always potent. Problem is the evaporation and drip was sporadic. And the ocasional cloud of kalk.

So i decided to try the k1 avast kalk stirrer. Nothing but inconsistency and disappointed. For example the first 3 days after I put new water and kalk in it works insanely good keeping my ph at 8.3 at night but spiking alk from 7.9 to 8.4 and calcium jumps from 400 to 500. Dosing 12 hours at night. After three days I do mot see it doing much of anything with alk dropping to 7.5 and calcium to 375. Of course I make the needed to part adjustments to keep things steady. But this is what happens.

I noticed the powder never gets consumed. I would never have to add powder for months as the level does not drop. The stirrer is slow and the motor is the loudest thing on my tank.

My guess is the kalk is a slurry on the first couple days then powder falls to bottom and stirrer is not strong enough to mix it up to saturate.

anyone else have these problems? Soda ash seems to increase ph much better.

looking for a good tester for saturation level. I am curious as to what is going on.

can somebody recommend a straight forward probe or tester that does not cause me to do math equations?

 

[ScottB]

I used to just mix up kalk in my ato then cover it with saran wrap. Always potent. Problem is the evaporation and drip was sporadic. And the ocasional cloud of kalk.

So i decided to try the k1 avast kalk stirrer. Nothing but inconsistency and disappointed. For example the first 3 days after I put new water and kalk in it works insanely good keeping my ph at 8.3 at night but spiking alk from 7.9 to 8.4 and calcium jumps from 400 to 500. Dosing 12 hours at night. After three days I do mot see it doing much of anything with alk dropping to 7.5 and calcium to 375. Of course I make the needed to part adjustments to keep things steady. But this is what happens.

I noticed the powder never gets consumed. I would never have to add powder for months as the level does not drop. The stirrer is slow and the motor is the loudest thing on my tank.

My guess is the kalk is a slurry on the first couple days then powder falls to bottom and stirrer is not strong enough to mix it up to saturate.

anyone else have these problems? Soda ash seems to increase ph much better.

looking for a good tester for saturation level. I am curious as to what is going on.

can somebody recommend a straight forward probe or tester that does not cause me to do math equations?

Hmmm. Sorry to hear. My setup (Reef Octo, but doubt that matters) has been rock steady. Every couple weeks I just dump in a cup of powder. I shoot for about 1.5" of powder in the stirrer.

It took me a couple weeks/months to figure out the dosing schedule, but APEX Fusion DOS makes that easy. The schedule now has 3 intervals at different rates. (It is posted above). I use it to solve only for pH, and use ESV 2-part via another DOS head to manage dKH.

I do have an inline EC meter, but honestly not sure I have looked at it in months. I just check my pH charts. After a week or two, they start drifting down and I refill. When I was looking at the EC, there was some noise there. At refill, the meter would hit max 10,000 and over time drift down just below 7000. So it certainly loses potency over time. It just did not really translate into tank measure volatility, dosing +4 liters into about 300G.



I have not noticed much noise in my dKH measures.

 

[Cjeippert]

Hmmm. Sorry to hear. My setup (Reef Octo, but doubt that matters) has been rock steady. Every couple weeks I just dump in a cup of powder. I shoot for about 1.5" of powder in the stirrer.

It took me a couple weeks/months to figure out the dosing schedule, but APEX Fusion DOS makes that easy. The schedule now has 3 intervals at different rates. (It is posted above). I use it to solve only for pH, and use ESV 2-part via another DOS head to manage dKH.

I do have an inline EC meter, but honestly not sure I have looked at it in months. I just check my pH charts. After a week or two, they start drifting down and I refill. When I was looking at the EC, there was some noise there. At refill, the meter would hit max 10,000 and over time drift down just below 7000. So it certainly loses potency over time. It just did not really translate into tank measure volatility, dosing +4 liters into about 300G.



I have not noticed much noise in my dKH measures.

I am going to try and put more powder in and more powder each week. Or twice a week. Maybe occasionally manually stir it up as well, since stirrer stick barely moves

 

[C. Eymann]

We use ~4gal MRC Nilsen style (sealed) reactors on our farm systems, with my kalk reactor at home, I would typically add two cups or so once a month.
however, we are pushing 10-12gal/day through the reactors at work, we typically add 2 full bags of Mrs Wages every two weeks, we see an definite trend in decline of tank pH for once tractors become exhausted, I can also tell visually now when a reactor is getting exhausted, the settled kalk at the bottom will start looking fluffier, flakey almost rather then settled powder

 

[Dennis Cartier]

I used to just mix up kalk in my ato then cover it with saran wrap. Always potent. Problem is the evaporation and drip was sporadic. And the ocasional cloud of kalk.

So i decided to try the k1 avast kalk stirrer. Nothing but inconsistency and disappointed. For example the first 3 days after I put new water and kalk in it works insanely good keeping my ph at 8.3 at night but spiking alk from 7.9 to 8.4 and calcium jumps from 400 to 500. Dosing 12 hours at night. After three days I do mot see it doing much of anything with alk dropping to 7.5 and calcium to 375. Of course I make the needed to part adjustments to keep things steady. But this is what happens.

I noticed the powder never gets consumed. I would never have to add powder for months as the level does not drop. The stirrer is slow and the motor is the loudest thing on my tank.

My guess is the kalk is a slurry on the first couple days then powder falls to bottom and stirrer is not strong enough to mix it up to saturate.

anyone else have these problems? Soda ash seems to increase ph much better.

looking for a good tester for saturation level. I am curious as to what is going on.

can somebody recommend a straight forward probe or tester that does not cause me to do math equations?

I have a K1 (and a K2). I used the K1 for awhile, but found that the saturation of the kalk would fall fairly rapidly. This led to inconsistent dKh levels, even though I was dosing a preset amount through it. Adding excess powder did not help the situation and I eventually twisted the stir bar off the K1unit by having too much undissolved kalk for it to mix.

I upgraded to the K2. Same issue, the potency would fall off after the kalk was initially refilled.

Then I switched to a Geo 8" kalk reactor. I was hoping the inclusion of the pump would be better at keeping things saturated. Nope. Same issue.

What I have found is that, reaching full saturation is easy the first time you add kalk to these reactors, but the excess kalk never really dissolves to keep the saturation up. My premise is that kalk powder has different particle sizes that are easier or harder to dissolve. They all dissolve fairly well in low pH RODI, but not so much in high pH, partially saturated kalkwasser solution. Adding fresh powder to a partially saturated only gives a small increase, much smaller than the quantity of added kalk would suggest should occur. Again, the premise being that the easiest to dissolve particles are being dissolved, and the larger, harder to dissolve particles don't.

I still use the Geo reactor, but I have converted it to being just a kalk resovoir with built in (initial) mixing. I extended the water intake tube to 1" from the bottom and pull from that. I put a reveresed check valve on the old water exit and that allows air to enter when enough vaccum is created inside to break the seal of the check valve. The volume of the Geo is a bit small though, so I still plan to switch to an old school barrel style reservoir eventually.

 

[Cjeippert]

I have a K1 (and a K2). I used the K1 for awhile, but found that the saturation of the kalk would fall fairly rapidly. This led to inconsistent dKh levels, even though I was dosing a preset amount through it. Adding excess powder did not help the situation and I eventually twisted the stir bar off the K1unit by having too much undissolved kalk for it to mix.

I upgraded to the K2. Same issue, the potency would fall off after the kalk was initially refilled.

Then I switched to a Geo 8" kalk reactor. I was hoping the inclusion of the pump would be better at keeping things saturated. Nope. Same issue.

What I have found is that, reaching full saturation is easy the first time you add kalk to these reactors, but the excess kalk never really dissolves to keep the saturation up. My premise is that kalk powder has different particle sizes that are easier or harder to dissolve. They all dissolve fairly well in low pH RODI, but not so much in high pH, partially saturated kalkwasser solution. Adding fresh powder to a partially saturated only gives a small increase, much smaller than the quantity of added kalk would suggest should occur. Again, the premise being that the easiest to dissolve particles are being dissolved, and the larger, harder to dissolve particles don't.

I still use the Geo reactor, but I have converted it to being just a kalk resovoir with built in (initial) mixing. I extended the water intake tube to 1" from the bottom and pull from that. I put a reveresed check valve on the old water exit and that allows air to enter when enough vaccum is created inside to break the seal of the check valve. The volume of the Geo is a bit small though, so I still plan to switch to an old school barrel style reservoir eventual

I wish I would have read and seen the discussion of these Kalk Stirrers inability to hold full saturation limewater before I purchased it. Oh well, this is a relatively cheap trial and error thing. I suppose I will go back to a sealed reservoir system. I am curious if the manufacturer of the actual Kalkwasser makes a difference. I use brs because they claim they have less impurities than everyone else through icp testing.

for those of you who get close to fully saturated limewater through your stirrers, what brand of kalk do you use?

anyone know what kalk ACI uses?

 

[Aimforever]

I use one of the heads of my APEX DOS. It pulls water from my RODI water storage tank and pushes it into my Reef Octo stirrer. This overflows the stirrer and it is a gravity feed from there into the sump return section.

The programming is super easy and very flexible, allowing me to dose at different rates over different periods of time. I highly recommend. My range is now 8.35 to 8.46 peak.

Amazing, I didn’t realize you could do that with the DOS, but now that I see how you did it, makes complete sense. Thank you!!

 

[Aimforever]

I wish I would have read and seen the discussion of these Kalk Stirrers inability to hold full saturation limewater before I purchased it. Oh well, this is a relatively cheap trial and error thing. I suppose I will go back to a sealed reservoir system. I am curious if the manufacturer of the actual Kalkwasser makes a difference. I use brs because they claim they have less impurities than everyone else through icp testing.

for those of you who get close to fully saturated limewater through your stirrers, what brand of kalk do you use?

anyone know what kalk ACI uses?

I’ve been using the K2 for a little while and the output has been holding steady/saturated so far. Are you stirring constantly? I also add enough powder to get about 4” in the bottom. Hopefully it keeps working well long term :/

In the first one, you just swap in sodium hydroxide for the sodium carbonate, the second recipe is more complicated.

Second New DIY Two Part Recipe with Higher pH Boost

In a previous thread, I posted a true two part DIY recipe: https://www.reef2reef.com/threads/new-diy-two-part-recipes-with-higher-ph-boost.344500/ But some folks may want to just swap the new ingredient into my 2/3 part recipe (as used by BRS, for example). Here's the original recipe link...

www.reef2reef.com

New DIY Two Part Recipes with Higher pH Boost

Here's a first crack at what may end up being multiple possible recipes for a DIY two part that either has a higher pH or can be made more concentrated than traditional two part recipes. This one has about twice the pH raising effect compared to a carbonate based two part, per unit of...

www.reef2reef.com

Randy I ordered some sodium hydroxide and am going to give it a try. I have a 500g system and mix up 15 gallons of 2 part at a time in rubbermaids so I can go several months before having to make more. This setup has worked great for me over the long term, but in my new system in a new home I have been working to improve on low pH issues.

My 2 part containers have snap on lids that lock in place but are probably not completely air tight. Some of the reading I’ve been doing makes me wonder if that could be part of the problem with pH on the alk component dropping over time?

I currently have about 7 gallons of mixed soda ash remaining. Could I top off this off to 15 gallons by adding the appropriate amount of sodium hydroxide (8 gallons RODI + 2264g sodium hydroxide)? My non-chemistry background would lead me think maybe I could see some of the pH benefit and transition gradually without wasting current alk component or would mixing the soda ash and sodium hydroxide be problematic?

Thanks again for the help!

 

[ScottB]

Amazing, I didn’t realize you could do that with the DOS, but now that I see how you did it, makes complete sense. Thank you!!

You are welcome.
One tip for you: Add your first DOS interval at 00:01 before trying to add another interval. Otherwise, you won't be presented with the option to "Add another interval".

 

[Randy Holmes-Farley Verified Community Expert]

I currently have about 7 gallons of mixed soda ash remaining. Could I top off this off to 15 gallons by adding the appropriate amount of sodium hydroxide (8 gallons RODI + 2264g sodium hydroxide)? My non-chemistry background would lead me think maybe I could see some of the pH benefit and transition gradually without wasting current alk component or would mixing the soda ash and sodium hydroxide be problematic?

I think I answered this in another thread, but CO2 entering slowly does not reduce alk unless the product precipitates. And dosing the mix sounds fine.

 

[brahm]

I have a K1 (and a K2). I used the K1 for awhile, but found that the saturation of the kalk would fall fairly rapidly. This led to inconsistent dKh levels, even though I was dosing a preset amount through it. Adding excess powder did not help the situation and I eventually twisted the stir bar off the K1unit by having too much undissolved kalk for it to mix.

I upgraded to the K2. Same issue, the potency would fall off after the kalk was initially refilled.

Then I switched to a Geo 8" kalk reactor. I was hoping the inclusion of the pump would be better at keeping things saturated. Nope. Same issue.

What I have found is that, reaching full saturation is easy the first time you add kalk to these reactors, but the excess kalk never really dissolves to keep the saturation up. My premise is that kalk powder has different particle sizes that are easier or harder to dissolve. They all dissolve fairly well in low pH RODI, but not so much in high pH, partially saturated kalkwasser solution. Adding fresh powder to a partially saturated only gives a small increase, much smaller than the quantity of added kalk would suggest should occur. Again, the premise being that the easiest to dissolve particles are being dissolved, and the larger, harder to dissolve particles don't.

I still use the Geo reactor, but I have converted it to being just a kalk resovoir with built in (initial) mixing. I extended the water intake tube to 1" from the bottom and pull from that. I put a reveresed check valve on the old water exit and that allows air to enter when enough vaccum is created inside to break the seal of the check valve. The volume of the Geo is a bit small though, so I still plan to switch to an old school barrel style reservoir eventually.

Hate to necro this thread, but I'm running into the same issue (outlined in a bigger discussion here - https://www.reef2reef.com/threads/ph-on-the-drop-cant-seem-to-isolate-cause-any-suggestions.907767/) and was wondering if anyone had a solution. When I first added my K2 I was seeing steady bumps in PH every time it dosed after a few months despite cleaning and replacing all the kalk it won't hold saturation. I had my suspicions so I added a PH probe to the reactor and then tried validating it by feeding the K2 from a reservoir with a batch of hand-mixed saturated kalk; low and behold after a month of struggling to get the PH inside the stirrer to hit 12+ as soon as it was pulling in from a batch of mixed kalk it shot up to 12.3. This, unfortunately, validates my hypothesis that the kalk stirrer despite being stirrer 24/7 and only dosing 2800ml during the evening is unable to saturate the kalk fully as it stands. Any suggestions what have folks done to resolve this?

Note the big spike at the end once I stopped pulling from the ATO reservoir and started from a premixed batch of Kalk.

While I didn't have a probe in the K2 in Feb you can see in my tank PH graph all the spikes as a reaction to it dosing.

and now my K2's ph probe is holding steady at 12.3 despite the unit dosing into the tank as the water coming to it from a saturated source.

Where as prior it was unable to keep the solution saturated; the bump is from me manually trying to stir it a little.

 

[Randy Holmes-Farley Verified Community Expert]

I don't have a great answer to you, except to note that lack of saturation control is one of the reasons I do not prefer dosing kalkwasser/limewater from a stirrer.

 

[Dennis Cartier]

Hate to necro this thread, but I'm running into the same issue (outlined in a bigger discussion here - https://www.reef2reef.com/threads/ph-on-the-drop-cant-seem-to-isolate-cause-any-suggestions.907767/) and was wondering if anyone had a solution. When I first added my K2 I was seeing steady bumps in PH every time it dosed after a few months despite cleaning and replacing all the kalk it won't hold saturation. I had my suspicions so I added a PH probe to the reactor and then tried validating it by feeding the K2 from a reservoir with a batch of hand-mixed saturated kalk; low and behold after a month of struggling to get the PH inside the stirrer to hit 12+ as soon as it was pulling in from a batch of mixed kalk it shot up to 12.3. This, unfortunately, validates my hypothesis that the kalk stirrer despite being stirrer 24/7 and only dosing 2800ml during the evening is unable to saturate the kalk fully as it stands. Any suggestions what have folks done to resolve this?

Note the big spike at the end once I stopped pulling from the ATO reservoir and started from a premixed batch of Kalk.

While I didn't have a probe in the K2 in Feb you can see in my tank PH graph all the spikes as a reaction to it dosing.

and now my K2's ph probe is holding steady at 12.3 despite the unit dosing into the tank as the water coming to it from a saturated source.

Where as prior it was unable to keep the solution saturated; the bump is from me manually trying to stir it a little.

My experiences with the kalk stirrers/mixers has been identical to what you saw. An inability to hold saturation using the surplus kalk in the reactor. Which is opposite to the expected behaviour of these reactors. My solution is to always dose from a still, premixed reservoir. So I use my Geo kalk reactor to do an initial mix, and then pull from that until the water level gets low and I refill and re-mix. It defeats the purpose of the reactor (convenience, low effort and little maintenance), but at least I get on-going, saturated kalk from it. I am currently re-filling a couple of times a week.

I discuss what I think is at the root of the issue in the thread below.

Why is Kalk so hard to dissolve?

I have been using kalk in a reactor off and on for years. I started with an Avast K1 and then moved to a K2. I now run a Geo 8" kalk reactor. I switched from the Avast's after I started monitoring the saturation using an EC probe and found that the reactors would start to lose saturation even...

www.reef2reef.com

 

[brahm]

My experiences with the kalk stirrers/mixers has been identical to what you saw. An inability to hold saturation using the surplus kalk in the reactor. Which is opposite to the expected behaviour of these reactors. My solution is to always dose from a still, premixed reservoir. So I use my Geo kalk reactor to do an initial mix, and then pull from that until the water level gets low and I refill and re-mix. It defeats the purpose of the reactor (convenience, low effort and little maintenance), but at least I get on-going, saturated kalk from it. I am currently re-filling a couple of times a week.

I discuss what I think is at the root of the issue in the thread below.

Why is Kalk so hard to dissolve?

I have been using kalk in a reactor off and on for years. I started with an Avast K1 and then moved to a K2. I now run a Geo 8" kalk reactor. I switched from the Avast's after I started monitoring the saturation using an EC probe and found that the reactors would start to lose saturation even...

www.reef2reef.com

oof, I spoke to Avast they suggested I put zip ties up the shaft.. Guess we'll see how that works. Worse case I dedicate more space to a 50-gallon container but I'd like to avoid that if possible.

 

[Midrats]

Stirrer’s like the Avast Marine have a Ph probe holder built in. This is so you can watch the saturation rate. A fully saturated solution is 12.3. As the kalk is used it will drop. At that point you just add more. Thats what’s so awesome about stirrers, you can’t add too much. It will only mix to the fully saturated level. No need to dump and start over. Be sure to allow it to settle before continuing to dose. Your stirrer should be pulling from the top of your saturated solution.

You can't add too much too a Brute trash can either, unless you want a weaker solution.

 

[Cjeippert]

oof, I spoke to Avast they suggested I put zip ties up the shaft.. Guess we'll see how that works. Worse case I dedicate more space to a 50-gallon container but I'd like to avoid that if possible.

Can you explain what zip ties up the shaft mean or show a pic. My k-1 stirrer also loses potency over time. I put new in every 2 weeks. The other premixed in a seal container doses much closer to full saturation and helps keep ph up at night. The stirrers do mot do much for ph for me, as I only dose a gallon to a gallon and a half a day. Curious about the zip ties

 

[brahm]

Can you explain what zip ties up the shaft mean or show a pic. My k-1 stirrer also loses potency over time. I put new in every 2 weeks. The other premixed in a seal container doses much closer to full saturation and helps keep ph up at night. The stirrers do mot do much for ph for me, as I only dose a gallon to a gallon and a half a day. Curious about the zip ties

I haven't done it yet, but essentially you take some zip ties, tie them around the shaft that spins the part that stirs the kalk in various locations and each one acts as an additional one in theory should act as an additional blade for mixing up the solution. I don't know how well it works yet; but this is the response I received from Avast Marine when asking about the potency drop of my k2.

There are ways to increase the potency of the kalk solution but we don’t publish it widely as it can be very tricky to dose correctly for the average aquarist. One very easy mod is to add a few zip ties to the rod above the stir bar. This will mix more aggressively and cause the kalk “layer” to rise up higher. You will dose a higher pH slurry doing this. Please be very careful though. pH 12.3 solution is 100x stronger than pH 10.3 solution. pH is a logarithmic scale. I would only suggest trying this if you have a well calibrated pH probe and the necessary controls in place to prevent overdose, and your current system isn’t supplying the alkalinity/calcium your system needs.

They also suggested I continue to use Mrs Wages over BRS (which I was planning on switching to) as they said they finer Mrs Wages mixes easier.

BRS tends to be really dense for some reason, and doesn't give any solubility advantages that we've seen. It can stress out the motor when too much is used due to the higher density. I would stick with the Mrs Wages and try a little more. But do the zip tie mod first, you may get the slurry you're looking for without needing to add more powder

 

[Cjeippert]

I haven't done it yet, but essentially you take some zip ties, tie them around the shaft that spins the part that stirs the kalk in various locations and each one acts as an additional one in theory should act as an additional blade for mixing up the solution. I don't know how well it works yet; but this is the response I received from Avast Marine when asking about the potency drop of my k2.



They also suggested I continue to use Mrs Wages over BRS (which I was planning on switching to) as they said they finer Mrs Wages mixes easier.

Good to know about trying better more fine kalk than brs. Brs said they tested their own and their own is the best….

 

[Operator Wrasse]

This was a great rabbit hole to go down. Lots of great information. I'd love to find the solution as to why the Kalk reactor doesn't hold saturation like a reservoir. You all have great hypotheses, though.

I'm under the impression that alk levels are dependent on pH and vice versa; higher pH allows more soluble alk to be available in the water column. When you're dosing Kalk and having pH fluctuations, how big are the swings between the 2 and what is truly acceptable? We're reaching a point where our scientific understanding is great, so would chasing a fairly stable pH be the best way to nail stable alkalinity?