Advice for a complete supplement dosing that utilizes Kalkwasser

[arking_mark]

The Hanna calcium checker gives folks more problems than most, and it is freakishly sensitive to calcium in the blank, requiring distilled water to be sure calcium is low enough in the blank to not give false low readings in the tank sample.

Funny thing is that my old self (~20 years ago) would have immediately added an alkalinity supplement to balance that calcium reading. LOL

My #1 rule in reefing is nothing good ever happens quickly in a reef tank.

 

[Lou Ekus]

I find it humorous that K+ elements does not contain the element K+. lol

Other than that, it seems OK, though I do not know if all of those ingredients are necessary or if the amounts present are sufficient.

@Randy Holmes-Farley I agree that it's kind of funny. But we don't consider potassium technically a "trace" element as it is in such high concentrations. In my opinion it falls more into the "main" or "minor" category.

 

[arking_mark]

@Randy Holmes-Farley So I'm getting some possible unexpected results. My initial dKH went up as expected with dosing, but seemingly "stalled" at 7.

This is a new 400L tank that was fully cycled on Nov 15th 2020. Intial dkh was low 7s (Brightwell Neomarine ASW) and was not being supplemented. Just this week I added a couple of mushrooms and a zoa to see how they would do. I'm wasn't planning on adding real coral till I start to see coralline algae start to form (and I don't see any yet, but it's been seeded from my mature tank).

This week, I transitioned my GHL to the new tank and my Alk was at 6.6dKH. I implemented the Kalk dosing and it went up to 7.2dKH, jumping as expected with the dosing and then came down to a steady "stalled" 7dKH. I'm not seeing those ~.25dKH jump as expected anymore after dosing (I'm still seeing expected ph jumps). I tested my old tank pre and post-dosing (Triton dosing) and got the expected increases, so the GHL still seems to be measuring dead on.

I don't think the tank is using up what is essentially 1dKH per day and I should see the jumps very shortly after dosing. Any ideas of what might be going on?

I did add a large CUC...but I can't think of anything in the tank consuming that much Alk.

 

[HuduVudu]

If you are willing to walk on the wild side you can read the thread linked in my signature block.

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley So I'm getting some possible unexpected results. My initial dKH went up as expected with dosing, but seemingly "stalled" at 7.

This is a new 400L tank that was fully cycled on Nov 15th 2020. Intial dkh was low 7s (Brightwell Neomarine ASW) and was not being supplemented. Just this week I added a couple of mushrooms and a zoa to see how they would do. I'm wasn't planning on adding real coral till I start to see coralline algae start to form (and I don't see any yet, but it's been seeded from my mature tank).

This week, I transitioned my GHL to the new tank and my Alk was at 6.6dKH. I implemented the Kalk dosing and it went up to 7.2dKH, jumping as expected with the dosing and then came down to a steady "stalled" 7dKH. I'm not seeing those ~.25dKH jump as expected anymore after dosing (I'm still seeing expected ph jumps). I tested my old tank pre and post-dosing (Triton dosing) and got the expected increases, so the GHL still seems to be measuring dead on.

I don't think the tank is using up what is essentially 1dKH per day and I should see the jumps very shortly after dosing. Any ideas of what might be going on?

I did add a large CUC...but I can't think of anything in the tank consuming that much Alk.

Folks often find similar issues when dosing limewater. Both abiotic and biological demand for alk rise as pH and alk rise, leading to a negative feedback loop that minimizes the observed alk rise.

You may also not be dosing as concentration of a solution as you assume.

Here's a related commend in an article of mine:

http://reefkeeping.com/issues/2005-01/rhf/index.htm

Habib Sekha (Salifert) has pointed out that limewater additions may lead to substantial precipitation of calcium carbonate in reef aquaria. This idea makes perfect sense. After all, it is certainly not the case that large numbers of reef aquaria will exactly balance calcification needs by replacing all evaporated water with saturated limewater. And yet, many find that calcium and alkalinity levels are stable over long time periods with just that scenario. One way that can be true is if the excess calcium and alkalinity that such additions typically dump into the aquarium are subsequently removed by precipitation of calcium carbonate (such as on heaters, pumps, sand, live rock, etc.).

 

[arking_mark]

Folks often find similar issues when dosing limewater. Both abiotic and biological demand for alk rise as pH and alk rise, leading to a negative feedback loop that minimizes the observed alk rise.

You may also not be dosing as concentration of a solution as you assume.

Here's a related commend in an article of mine:

http://reefkeeping.com/issues/2005-01/rhf/index.htm

Habib Sekha (Salifert) has pointed out that limewater additions may lead to substantial precipitation of calcium carbonate in reef aquaria. This idea makes perfect sense. After all, it is certainly not the case that large numbers of reef aquaria will exactly balance calcification needs by replacing all evaporated water with saturated limewater. And yet, many find that calcium and alkalinity levels are stable over long time periods with just that scenario. One way that can be true is if the excess calcium and alkalinity that such additions typically dump into the aquarium are subsequently removed by precipitation of calcium carbonate (such as on heaters, pumps, sand, live rock, etc.).

Thanks!

 

[arking_mark]

If you are willing to walk on the wild side you can read the thread linked in my signature block.

Not seeing the signature block. Maybe because I'm on mobile?

 

[ReefBeta]

About pH bump, I was looking into that earlier and found that slower dosing speed keeps pH at higher level. So it will be best to have a variable speed dosing pump to dose it consistently throughout the day. I'm using a versa pump and only adjusting the dosing speed. Slower dose will also limit the local concentration of alk and calcium, thus reduce precipitation, I think. I do have some precipitation at the point the kalk solution gets into the tank, in the filter sock chamber. Haven't found visible precipitation else where so far.

 

[arking_mark]

About pH bump, I was looking into that earlier and found that slower dosing speed keeps pH at higher level. So it will be best to have a variable speed dosing pump to dose it consistently throughout the day. I'm using a versa pump and only adjusting the dosing speed. Slower dose will also limit the local concentration of alk and calcium, thus reduce precipitation, I think. I do have some precipitation at the point the kalk solution gets into the tank, in the filter sock chamber. Haven't found visible precipitation else where so far.

You beat me my next adjustment...and automation update. Coming soon...

 

[HuduVudu]

Not seeing the signature block. Maybe because I'm on mobile?

Soda poppin' ... and how to dose infinite Kalk

Ok, how I arrived at this crazy simple stupid idea was kinda like this: It started a long time ago when wet dry filters were still dominant and only the cool kids built Berlins. I had gotten back into the hobby after being in the Philippines and I was absolutetly enamored with live coral, I...

www.reef2reef.com

 

[arking_mark]

Just a quick update. I switched up my automation and now have a fixed rate of delivery of Kalk.

1. 2.5ml/min of kalk which delivers 3600ml of kalk or 1dKH for my 400L tank. (Kalk stirrer and variable speed doser)
2. Kalk is only dosed if my ph is below 8.3, dKH is below 8.5 (ph probe, dKH monitor), and my sump high-level senor is not triggered (float switch)
3. 2x a day ATO (dosing pumps) with RODI if salinity is above 1.025 (conductivity probe) and with AFW if below 1.025.

With this setup I seemingly have settled in at around 8.07 (which was my average with the 4x dosing regiment) and my Alk has seemingly locked in at 7dKH.

The Alk feels a little low, but I'll let things run for a while longer before changing up anything. I'll probably just up the kalk dosing. I'm just really surprised by this number as the tank is 2.5 months old with 3 Mollies, 1 Bella Goby, a large CUC, 2 small mushrooms, and a small zoa frag.

I'm pretty happy with the ph boost. I'll have to monitor more to see if there are any swings.

I'll probably add Bio-magnesium this weekend and the trace elements. If my tank is sucking up 1dKH a day...something is using it. Maybe the CUC (mostly snails) and hoping for some coralline algae.

Once I see coralline algae, I'll begin to migrate stuff from my old tank.

 

[arking_mark]

One interesting thing to note is that with such a slow rate of delivery, the output of the Kalk stirrer is not consistent. It comes out in small spurts...due to water cohesiveness.

 

[arking_mark]

@Randy Holmes-Farley So it appears that dosing at 2.5ml/min matches my evaporation which means I'm at the limit of using Kalkwasser in a tank with no coral. What am I missing?

The Alk is steady at 7dKH and PH at 8.04 - 8.06.

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley So it appears that dosing at 2.5ml/min matches my evaporation which means I'm at the limit of using Kalkwasser in a tank with no coral. What am I missing?

The Alk is steady at 7dKH and PH at 8.04 - 8.06.

I do not know if you are missing anything, unless the limewater (kalkwasser) is not saturated. That is a fundamental limit to dosing calcium hydroxide in top off. It was enough for my tank for 20 years, but many tanks it is not enough. Adding vinegar can allow a bit more to dissolve. But that is a complication.

Many folks dose a two part (or use a CaCO3/CO2 reactor) in addition to, or instead of, limewater.

 

[arking_mark]

I do not know if you are missing anything, unless the limewater (kalkwasser) is not saturated. That is a fundamental limit to dosing calcium hydroxide in top off. It was enough for my tank for 20 years, but many tanks it is not enough. Adding vinegar can allow a bit more to dissolve. But that is a complication.

Many folks dose a two part (or use a CaCO3/CO2 reactor) in addition to, or instead of, limewater.

Hey @Randy Holmes-Farley, I'm aware of that limitation. Just why would I hit it with no real coral to speak of?

I also decided to recalibrate my GHL since it started to deviate a lot with my Hanna. New measurements are more in-line with expectations. My ASW now reads around 7dKH which aligns with the Hanna and my tank is 7.7dKH (Hanna has 8.1dKH).

My ph has really looked good with the constant 2.5ml. I'm now 8.1-ish for most of the day.

 

[arking_mark]

About pH bump, I was looking into that earlier and found that slower dosing speed keeps pH at higher level. So it will be best to have a variable speed dosing pump to dose it consistently throughout the day. I'm using a versa pump and only adjusting the dosing speed. Slower dose will also limit the local concentration of alk and calcium, thus reduce precipitation, I think. I do have some precipitation at the point the kalk solution gets into the tank, in the filter sock chamber. Haven't found visible precipitation else where so far.

This is spot on so far. Since starting the 2.5ml/min dosing, the ph has slowly and steadily risen. I'm at a high of 8.15. Great advice!

 

[arking_mark]

This is spot on so far. Since starting the 2.5ml/min dosing, the ph has slowly and steadily risen. I'm at a high of 8.15. Great advice!

I'd be thrilled if it stays above 8.1. I'm loving kalkwasser so far...

 

[Reefinmike]

I'd be thrilled if it stays above 8.1. I'm loving kalkwasser so far...

I struggled with high CO2 and low pH for years. I did everything, including a max dose of kalkwasser and I was lucky to average 8.00pH. it'd drop under 7.60 without my skimmer, kalk, glass lids, soda ash etc etc. I'm now skimmerless and pH stays within 0.07 of 8.30. Our alk testers are very similar; I think you may be able to implement some of what I've done here: https://www.reef2reef.com/threads/i...-and-dos-for-stable-alkalinity-and-ph.784144/

 

[Randy Holmes-Farley Verified Community Expert]

Hey @Randy Holmes-Farley, I'm aware of that limitation. Just why would I hit it with no real coral to speak of?

I also decided to recalibrate my GHL since it started to deviate a lot with my Hanna. New measurements are more in-line with expectations. My ASW now reads around 7dKH which aligns with the Hanna and my tank is 7.7dKH (Hanna has 8.1dKH).

My ph has really looked good with the constant 2.5ml. I'm now 8.1-ish for most of the day.

Limewater (kalwasser) is somewhat self limiting as dosing more leads to higher demand due to the pH and alk rise.

But have you somehow measured the potency of the limewater you are dosing?

 

[arking_mark]

Limewater (kalwasser) is somewhat self limiting as dosing more leads to higher demand due to the pH and alk rise.

But have you somehow measured the potency of the limewater you are dosing?

I'm using BSR Kalk and a KS-100 stirrer and pH is reflecting dose added. Last couple of dKH readings have been going up so maybe substrate/rock/CUC was absorbing the initial dosing and now the numbers are rising.

With the re-calibrated GHL, my dKH is showing about a .2dKH drop in 6hrs (I stopped dosing kalk last night to see consumption). If that is roughly accurate, I should be seeing ~.2dKH increase per day. Given that my ASW is 7dKH-ish and my current tank reading is 8.1 and I've been running for about a week with kalk, I'm thinking things are accurate enough for discussion. I'll keep monitoring but am still perplexed about what is consuming the Kalk. I'll also look to measure the potency of the kalk. Any easy way to do that?