Dissolving the Kalkwasser powder in the Vinegar first

[Erasmus Crowley]

Can anyone please give me an idea why I can't get Seachem kalkwasser to dissolve no matter what I do? Even less than half of a teaspoon in a gallon won't dissolve. Seriously.

I will see if the stuff dissolves in vinegar after I figure out why it won't dissolve in water. Then I'll let you know my result.

To my mind, there are at least 3 reasons why kalk would seem like it isn't dissolving at all.

1. The container it was stored in wasn't airtight. Because of that, water vapor and CO2 leaked in, allowing the calcium hydroxide to change into calcium carbonate. Calcium carbonate is basically not soluble in water in the amounts that we would appreciate it, and the vast majority would sink to the bottom.
2. Your RODI filter isn't functioning properly. If the water coming through already has a bunch of calcium, magnesium, flouride, and other minerals in it, then the addition of the calcium hydroxide might cause those preexisting minerals to instantly crash out of solution.
   
3. You're mixing your RODI with your kalkwasser powder and mixing it overnight with some kind of apperatus. The stirring would introduce a huge amount of CO2 and precipate out all the calcium hydroxide as calcium carbonate, effectively neutralizing it all.

So the next question is, in these conditions would adding vinegar help?

Short answer is yes. Sort of. Vinegar is acetic acid. Calcium carbonate is much more soluble in acetic acid than it is in plain water. It will form calcium acetate.

The downside is that when calcium acetate, or plain acetic acid are put in the tank, they are quickly consumed by bacteria which causes a drop in dissolved oxygen and a spike in bacteria populations. You're doing the exact same thing that other people call Carbon Dosing. If your nutrients (phosphorus and nitrogen) are very low, then carbon dosing in large amounts might strip the water completely which has been observed to cause problems with SPS coral. So proceed at your own risk, and maybe read up on carbon dosing with vinegar to get an idea how much is safe to add in a single day.

 

[Oldsalt]

I just dissolve it in vinegar first then add the RO and it seems to work ok. Definalty more potent than without the vinegar. So your saying the kalk won't dissolve at all in the water, it must become cloudy surly?

There will always be some precipitant but you should test the Alkalinity of the clear water after it settles to see if any has actually dissolved.

No it won't dissolve at all. Most of the powder settles to the bottom and the rest floats on top of like ice on a lake. It stinks badly too. Alkalinity of the water in between totally unaffected. I tried stirring it, or keeping a pump on in the bucket all to no avail. Powder keeps settling and rising after I stop stirring or turning pump off.

It has to be a bad batch. Bought it online so sending it back will cost me more than I spent getting it in the 1st place.

 

[Hitman]

Sounds like your Kalk is bad. Mine is like a fine powder and dissolves almost instantly.

 

[The Opinionated Reefer]

As above, if the container has not been air tight then it will have gone bad.

 

[Oldsalt]

I sent a message to the dealer and they're sending me a brand new container. I wasn't the only client to get a bad batch.