Kalkwasser confusion

[Mr. Comer]

Hi,
I two part dose for my home tank and keep a stable dkh of 9.6 and ca of 420. My office tank is a 30g with a 4 headed duncan, dozen heads of acans, a 1" toadstool, small palua leather, and several dozen zoas. So I don't have a very small ca/dkh demand. I'm using kalkwasser at max concentration at 2 teaspons per gallon and replacing topping of 5 gallons a month. Last month I dosed ca/alk to bring the tank back to the mid 9's for dkh and 440 for ca. Now I'm back down to 7.2 dkh and 410 ca. This is the third month in a row my kalkwasser isn't keeping up. Am I missing something?

[Nano sapiens]

Kalkwaser, even at full saturation strength, may not be able to keep up with a tank that has a good number of calcifying organisms. One way to increase the amount of kalkwasser that can be saturated in solution is by adding vinegar (Google that one for the correct procedure), which may be enough for your system. If that still doesn't do it, then you can add 2 part in addition to the fully saturated kalkwasser to keep up with demand.

[bertoni]

I agree that Kalk sometimes can't keep up with demand. You could try adding 15 ml of Kalk and 45 ml of vinegar per gallon to see whether that is enough. This article has more:

http://reefkeeping.com/issues/2005-01/rhf/index.htm#7

[downbeach]

One of the problems with using kalk in a top off is the fact that the amount you can add will vary with the evaporation rate, especially in a smaller system where there is less water/elements in reserve, to draw on. With the weather moderating a bit this time of year, you may be getting more fresh air(less CO2), in your systems surrounding atmosphere, giving you a bump in pH, and a little more calcification taking place using up a bit more of your Ca and alk. I think I would just get some CaCl and baking soda or soda ash, make some solutions, and dose by hand for a while to keep your numbers where you want them. If you find yourself dosing a lot you might consider going to dosing pumps.

[Mr. Comer]

Looks like I'll have to dose. I thought I could get away with Kalk only for this low of a ca/alk demand. Here is a pic of the 30g.http://uploads.tapatalk-cdn.com/20161108/e930df5530196bc140dd2da70657f2e2.jpg


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[downbeach]

How often are you doing WC's? What salt mix at what SG? What are you using to measure your SG?

[Mr. Comer]

I'm using the same BRS refractometer as my main reef. It is calibrated each time with calibration fluid and running at 1.026. I'm using reefcrystals so DKH/Ca/Mag are a little elevated over my target 9.4/420/1400 target. No3 and po4 are zero but I usually like to have both read a little something. I'm using Hannah for po4 and dkh and Rea Sea for ca and mg.

[downbeach]

OK, those are good devices/kits. I would probably make sure to keep a regular timetable with the WC's, so those elements are replaced/replenished around the same time, keep using the saturated kalk, and manually dose the Alk and Ca when needed. It doesn't sound like you need too much, try adding ~ 25ml of Ca and alk a week and retest.

[bertoni]

If the coralline algae take off, the tank could consume 2-3 dKH per day. :) Looks like a nice system!

[Mr. Comer]

I two part dose for my main tank but I have a lot more corals. This is my first time I've used Kalk and I thought it could keep up with a low /medium demand tank. Here is a gratuitous pic of my main tank. Sorry for the big pics, I'm not sure why taptalk is loading these so large :)
http://uploads.tapatalk-cdn.com/20161109/e1ecf798dd151fafb3fa9ecbb04ef6bb.jpghttp://uploads.tapatalk-cdn.com/20161109/06dbcaf8b3dfb0984fce5fc6b201d292.jpg


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[Walla2GSP]

Just out of curiosity what is your magnesium? I have difficulty keeping Alk/Ca elevated with kalkwasser in my 35 gallon unless I also dose Mag to maintain 1450 to 1500.

[Mr. Comer]

Last night I tested the Mg and it was at 1440. I did notice that my ATO container had a lot of kalk pasty floating on the top. I usually use a mj1200 in my 5g bucket to stir. Maybe I need to add a little calk at a time instead of adding it all at once?

[blasterman789]

Just out of curiosity what is your magnesium? I have difficulty keeping Alk/Ca elevated with kalkwasser in my 35 gallon unless I also dose Mag to maintain 1450 to 1500.

Ditto...drops like a rock unless I keep my mag up there as well.

Calcium hydroxide, contrary to myth, is not balanced. The alk component that reacts with water in your tank is much, much higher than calcium.

Kalk water also settles out in large storage tanks with the denser material being near the bottom. Need to be stirred at least once a day in my book.

[pisanoal]

Ditto...drops like a rock unless I keep my mag up there as well.

Calcium hydroxide, contrary to myth, is not balanced. The alk component that reacts with water in your tank is much, much higher than calcium.

Kalk water also settles out in large storage tanks with the denser material being near the bottom. Need to be stirred at least once a day in my book.

The saturated solution will not settle. What you are seeing is un-dissolved lime/impurities. You can get more lime into your system if you stir and suspend this un-dissolved stuff. But there are varying levels of opinion on whether or not that is good for the tank.

[bertoni]

Calcium hydroxide, contrary to myth, is not balanced. The alk component that reacts with water in your tank is much, much higher than calcium.

Calcium hydroxide provides calcium and alkalinity at the exact ratio of pure calcium carbonate. It's actually formed from calcium carbonate by heating it:

CaCO₃ -> CaO + CO₂

The reverse occurs (indirectly) in our tanks. This article has more:

http://reefkeeping.com/issues/2005-01/rhf/index.htm#1

[downbeach]

Fully saturated limewater(kalk) is 2 teaspoons per gallon of RO/DI water. If you add more it will settle to the bottom of the container, until you add more plain water, and it can further disolve. So, what you usually see in the bottom of an ATO container is a combination of excess kalk(more than the 2 tsp. per gal.), some impurities, and possibly some CaCo3 that has formed at the surface of the kalk liquid due to contact with CO2 in the atmosphere, and has settled to the bottom(a loose fitting lid will go a long way to mitigate this issue).

Some reading, if interested:

http://reefkeeping.com/issues/2003-05/rhf/feature/index.php
http://reefkeeping.com/issues/2005-01/rhf/index.php
http://reefkeeping.com/issues/2005-07/rhf/index.php#5