Can I infuse my vinegar dose into my kalk stirrer?

[TWYOUNG]

I'm frustrated with how quickly my kalk loses potency even in a stirrer, (determined by pH testing), and the large amt of undissolved powder which accumulates in the bottom of the stirrer. What I am considering doing is splicing my vinegar dose, (currently 85 mls per day), into my RODI water which flows into the stirrer. My daily kalk dose is currently 3L per day so I'd essentially be adding 85 mls of vinegar to each 3 liters of kalk. Could this work to continue my carbon dosing while also increasing the solubility and potency of my kalk solution?

 

[Randy Holmes-Farley]

While perhaps technically tricky, that will work, but it will not reduce the large amount of undissolvable calcium carbonate that accumulates. It will just allow more calcium hydroxide to dissolve into the water moving through it.

If it got to the point where no more calcium hydroxide is present, and only calcium carbonate is dissolving, the potency will be quite low.

 

[rishma]

Your predicament is exactly why I don’t like Kalk stirrers. I think the design concept frequently results in inconsistency and unsaturated solution. I am not sure vinegar will help with consistency.

 

[TWYOUNG]

Your predicament is exactly why I don’t like Kalk stirrers. I think the design concept frequently results in inconsistency and unsaturated solution. I am not sure vinegar will help with consistency.

The entire reason I got the stirrer was I "thought" the closed system would prevent calcium carbonate precipitation.

 

[TWYOUNG]

While perhaps technically tricky, that will work, but it will not reduce the large amount of undissolvable calcium carbonate that accumulates. It will just allow more calcium hydroxide to dissolve into the water moving through it.

If it got to the point where no more calcium hydroxide is present, and only calcium carbonate is dissolving, the potency will be quite low.

As I stated to rishma I got the stirrer because I thought the closed system would prevent calcium carbonate precipitation since there's no contact with room air.

 

[Randy Holmes-Farley]

Most folks do not report having large amounts of undissolvable material.

How are you measuring the potency?

 

[TWYOUNG]

Most folks do not report having large amounts of undissolvable material.

How are you measuring the potency?

pH, which drops from a max of around 12.2 to below 11.0 in a couple weeks.

 

[Randy Holmes-Farley]

pH, which drops from a max of around 12.2 to below 11.0 in a couple weeks.

Well, that is seriously depleted.

What are you using for source water?

 

[TWYOUNG]

Well, that is seriously depleted.

What are you using for source water?

RODI from my own system with separate anion and cation plus a mixed bed resin. Zero TDS output.

 

[Randy Holmes-Farley]

RODI from my own system with separate anion and cation plus a mixed bed resin. Zero TDS output.

No special aeration of that water after production?

 

[TWYOUNG]

No special aeration of that water after production?

No. I looked back through my notes and here's a breakdown of my management of the stirrer. It actually takes about 4 weeks for the pH drop I stated.

5/16/24 Stirrer initiated with 100 gms BRS Kalk powder.

5/19/24 Kalk pH 12.2

6/16/24 Kalk pH 11.6, 100 gms kalk powder added and pH rose to 12.2 when tested six hours later.

6/20/24 pH 12.1

8/2/24 PH 11.3

9/8/24 pH 11.3

10/6/24 100 gms kalk powder added

At present I have about 2 inches of powder in the bottom of the stirrer so I don't think I can add more without emptying out what's in there. With no prior experience with stirrers I'm not sure what the normal routine is for adding kalk and cleaning out the reactor. I didn't expect it to have significant residue nor require regular cleaning thus I thought as long as a decent amount of slurry was in the bottom I was good!

 

[TWYOUNG]

No special aeration of that water after production?

Well, as you can see from the pics the vinegar is doing "something". After one day the cylinder of the stirrer looks like I cleaned it. Not sure if anything on the bottom will dissolve but I'll be watching and measuring it for the next couple of weeks to see.

 

[rishma]

Well, as you can see from the pics the vinegar is doing "something". After one day the cylinder of the stirrer looks like I cleaned it. Not sure if anything on the bottom will dissolve but I'll be watching and measuring it for the next couple of weeks to see.

That’s pretty interesting!

since pH won’t be a good indicator of potency, will you track alkalinity in the tank to see if this helped?

Not sure if you can set up a separate reservoir but if you decide the stirrer won’t give you what you want, you will find that simply mixing a large batch of kalkwasser in a container with a lid will keep it stable and saturated long term. For many years I just mixed it in a remote 35 gallon brute trash can with a lid and dosed it. Without stirring or aeration, there was no meaningful change in potency for months. Dosing pumps can pull the fluid from a long way so I just ran 1/4” RO tubing to my trash can.

My current set up only has room for a small container, but I can still mix enough volume for a month at a time and it works well.

 

[TWYOUNG]

That’s pretty interesting!

since pH won’t be a good indicator of potency, will you track alkalinity in the tank to see if this helped?

Not sure if you can set up a separate reservoir but if you decide the stirrer won’t give you what you want, you will find that simply mixing a large batch of kalkwasser in a container with a lid will keep it stable and saturated long term. For many years I just mixed it in a remote 35 gallon brute trash can with a lid and dosed it. Without stirring or aeration, there was no meaningful change in potency for months. Dosing pumps can pull the fluid from a long way so I just ran 1/4” RO tubing to my trash can.

My current set up only has room for a small container, but I can still mix enough volume for a month at a time and it works well.

Yes I'll be closely watching my alkalinity. I've been requiring soda ash,(currently 75 mls per day but it varies), in addition to my 3 liters of kalk so I'll see if that decreases. I've gone the route of 5 gallon carboys and 30 gallon trash cans but always felt like I ended up with as much residue as kalk powder I originally put in. I was always paranoid about air exposure causing precipitate and even considered a floating styrofoam "lid" on my waste can. I'm likely overthinking this whole thing but I really thought the totally closed system of the stirrer would eliminate all calcium carbonate precipitation. I don't have a ton of stony coral but I do have a heavy coating of coralline growing on my rock and the back wall of my tank.

 

[rishma]

Yes I'll be closely watching my alkalinity. I've been requiring soda ash,(currently 75 mls per day but it varies), in addition to my 3 liters of kalk so I'll see if that decreases. I've gone the route of 5 gallon carboys and 30 gallon trash cans but always felt like I ended up with as much residue as kalk powder I originally put in. I was always paranoid about air exposure causing precipitate and even considered a floating styrofoam "lid" on my waste can. I'm likely overthinking this whole thing but I really thought the totally closed system of the stirrer would eliminate all calcium carbonate precipitation. I don't have a ton of stony coral but I do have a heavy coating of coralline growing on my rock and the back wall of my tank.

I used a conductivity meter to measure saturation of my Kalk. It was virtually unchanged over the course of my storage. Nothing fancy to keep air out. Randy wrote an article years ago that showed this data. I found it to be true for me too.

I always had precipitates at the bottom. Probably because I was using pickling lime with impurities. But the clear liquid I dosed stayed saturated. That’s what mattered to me.

 

[TWYOUNG]

I used a conductivity meter to measure saturation of my Kalk. It was virtually unchanged over the course of my storage. Nothing fancy to keep air out. Randy wrote an article years ago that showed this data. I found it to be true for me too.

I always had precipitates at the bottom. Probably because I was using pickling lime with impurities. But the clear liquid I dosed stayed saturated. That’s what mattered to me.

Aren't conductivity meters expensive? If I had one how does it indicate saturation and would vinegar affect those readings?

 

[Randy Holmes-Farley]

Aren't conductivity meters expensive? If I had one how does it indicate saturation and would vinegar affect those readings?

Saturated kalk is about 10.3 mS/cm. Vinegar plus extra kalk will raise that.

Costs vary from about $50 to over a thousand.

 

[rishma]

Aren't conductivity meters expensive? If I had one how does it indicate saturation and would vinegar affect those readings?

The one I had, that has since died, was a PinPoint brand and cost me $100 which was quite expensive to me. But I used it for salinity too. Sadly, I have not replaced it. I remember that saturated was 10.3 mS/cm. That is temp dependent but I just mixed until it was close and stopped changing.

 

[A_Blind_Reefer]

Out of curiousity have you tried less Kalk powder introduced more often? When I ran a Kalk stirrer, I found that I had to top it up with fresh Kalk weekly to maintain potency. I could add more and stretch it to two weeks, but there would be a slight decline in potency. No way I could have made a month. I finally decided to tackle modifying things to eliminate the stirrer. Not due to potency issues but as it was in the sump, I’m blind as a bat, and I’m too stupid to remember to grab a mask when I refilled it and got tired of breathing Kalk dust, banging my head under the tank, and poking my eyes on the door popper/plungers.

 

[TWYOUNG]

Out of curiousity have you tried less Kalk powder introduced more often? When I ran a Kalk stirrer, I found that I had to top it up with fresh Kalk weekly to maintain potency. I could add more and stretch it to two weeks, but there would be a slight decline in potency. No way I could have made a month. I finally decided to tackle modifying things to eliminate the stirrer. Not due to potency issues but as it was in the sump, I’m blind as a bat, and I’m too stupid to remember to grab a mask when I refilled it and got tired of breathing Kalk dust, banging my head under the tank, and poking my eyes on the door popper/plungers.

Interesting point. How much,(deep), should the slurry be in the bottom of the stirrer before it needs to be removed and started fresh?