Question for Kalwasser experts

Roks-Sharky

Roks-Sharky

Member
I have 2 tanks 90 & 150. Upstairs I have a 30 gallon rubber-maid trashcan hidden in a closet that I keep filled with R/o water. It feeds down to the tanks and automatically tops off the evaporated water.

If I put a power head and keep just the right amout of Kalwasser in that trashcan, will I run into any problems? This water keeps my tanks going for about ten days. But I genrally add to it once or twice a week. If I add three gallons, I would also add the correct amount of kalkwasser.

I always read make small batches of kalwasser, use it while it's fresh, don't let a flim form, precipitate is bad. etc etc etc. Some book instructions conflict the instructions on the bottles. It's very hard to figure out what makes a batch bad, unless you are a chemist.

Actually I already added the power head and kalwassser to the trashcan I just want to know if you think it was a bad idea.

Thanks
 
C

cheeks69

Wannabe Guru
RS STAFF
RHF:
The result of this reaction is visually obvious. The calcium carbonate can be seen as a solid crust on the surface of limewater that has been exposed to the air for a day or two (do not bother to remove this crust, it may actually be protecting the underlying limewater from further penetration by carbon dioxide). The formed solids also settle to the bottom of the container (as described above). Since solid calcium carbonate is not an especially useful supplement of calcium or alkalinity, this reaction has the effect of reducing the limewater’s potency. With sufficient exposure to air, such as by aeration or vigorous agitation, this reaction can be driven to near completion, with little calcium or hydroxide remaining in solution.

This reaction is the basis of the claims by many aquarists that limewater must be protected from the air. It is also the basis of the claim that Nilsen reactors are to be preferred over delivery from still reservoirs of limewater. Neither of these claims, however, stands up to experimental scrutiny, as I showed in a previous article. In a still reservoir that is not aerated, however, the potency is stable for a period adequate to permit dosing. Figures 3 and 4 show the conductivity of the limewater in my 44-gallon limewater reservoir over a three-week period. It was simply covered with a loose fitting plastic lid. It is apparent from the conductivity that the potency does not decrease significantly over time.
Click to expand...
 
Roks-Sharky

Roks-Sharky

Member
Re: Question for Kalkwasser experts

Jeez, I skimmed the link, I'm still confused!

I see some people must have tried what I am doing.

Should I aerate the water or not?

What's your vote?
 
Dentoid

Dentoid

Smile Maker
PREMIUM
1. Do not aerate.
2. Go back and read the article over and over until you understand it. (Skimming pertinent reef information is not allowed).
 
Roks-Sharky

Roks-Sharky

Member
Power head is recommended for a 10-30 gallon tank, trashcan is 30 gallons when full, with full-time aeration, there is a still a crust.

I will not aerate, but I should/can use the powerhead only to mix it initiatially, correct?

I will print out the article a read completely.

But since I am blinded by all those chemical equations, can you tell me what I am adding to my tank with the aerated water versus what am I adding to my tank with settled water?

Make a nice analogy for me: fine wine versus vinegar?

Rust versus iron filings?

Mayo versus oil & water?
 
Jynx

Jynx

Member
I know that I'm jumping in here late and I don't profess to be an expert on calcium chemistry, but this is the way that I think about kalkwasser and it's reaction with air.
Air contains small amounts of carbon dioxide. Kalkwasser is saturated with calcium ions. At the surface of your container of kalkwasser, the calcium reacts with the CO2 and changes to calcium carbonate. Calcium carbonate is pretty insoluble and becomes solid forming at thin skin. This skin forms a barrier between the air and the water and it from reacting with any more CO2, so the solution does not continue to loose calcium ions.
If you are bubbling air through the kalkwasser, you would be providing an endless supply of new air surfaces to interact with your kalkwasser and the ionized calcium levels should constantly drop.
Hope this helps and if I'm not understanding this process correctly, hopefully a real expert will chime in.
 
J

jg2269jg

Member
hey sorry to jump in here but i mix the kalk in a container and let the mix sit for about an hour or two until the mix settles then i use a airline tub to pull just the middle limewater out of the mixing container and put that into the dispensing container. When i do that i make sure i dont get the bottom percipitate or the top film just the limewater is this correct or am i doing it wrong thanks
 
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