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View Full Version : Please help: Kalk and precipitation


Hephalump
07/23/2011, 11:32 AM
Hi all, I just started dosing kalk with my ato about a week ago. I have been having trouble keeping my alk up, and I am getting calcium carbonate precipitation all over the place...even on my front glass. Here are the parameters that I have tested:

Alk: 6.7 on salifert test kit
Calcium: off the chart on API test kit, I estimate in the high 500's
PH: somewhere between 7.7 and 8.0 on API test kit (I can never read that stupid color chart)

My tank is 65 gallons with about 10 gallons in the sump. I evaporate about 1 gallon of water per day and have the kalk mixed at 2 tsp per gallon.
Every night I add 60 ml of B ionic part 1 with a slow drip and it tests to around 8. twenty four hours later it is back to around 6.7. I have the ato dripping into the sump right next to the return pump with a second powerhead pointed at it.
My tank is very lightly stocked. two ocellaris clowns, and one yellow watchman goby, some hermits and snails, and a cleaner shrimp. I have a few small corals, but and they are not really looking very well, and would not account for such a tremendous drop in alk.

Can anyone offer me some insight on how to keep my alk more stable and stop the calcium precipitation?

bertoni
07/23/2011, 05:54 PM
Depending on how high the calcium is, that could be part of the problem. Magnesium can be an issue, too, but both of these possibilities are rare. I think some measurements on those parameters would be useful to rule out some possibilities, even so.

That drop in a 24 hour period isn't all that large, if there's coralline in the tank. I had tanks that dropped 2-3 dKH per day from coralline growth, with no stony corals in the tank.

Are you seeing whitish or tannish buildups? Or are you seeing more like dust particles? I might try dosing with baking soda for a few days, to see whether a low-pH supplement works a bit better for you.

Hephalump
07/23/2011, 06:46 PM
There's definitely a good amount of coraline algae in the tank, but I was under the impression that dripping kalkwasser would keep the alkalinity stable. I'll definitely try dosing with baking soda and see if that helps.

I've never tested or dosed for magnesium, so I wouldn't be surprised if it were low. looks like I'll be purchasing a test kit for that soon.

The deposits on the front glass are white and take quite a bit of scraping to get off.

Thanks for the reply.

bertoni
07/23/2011, 07:37 PM
Sometimes kalk can keep up with the alkalinity consumption. Some tanks require more supplementation than kalk can provide, though, because it's a very dilute supplement.

If the kalk is added too rapidly, it might cause the kind of precipitation that you're seeing. I'd look into that. A peristaltic pump or something that produces a very low flow is best.

bertoni
07/23/2011, 07:37 PM
Sometimes kalk can keep up with the alkalinity consumption. Some tanks require more supplementation than kalk can provide, though, because it's a very dilute supplement.

If the kalk is added too rapidly, it might cause the kind of precipitation that you're seeing. I'd look into that. A peristaltic pump or something that produces a very low flow is best.

Hephalump
07/24/2011, 01:10 AM
Would lowering the concentration of the kalkwasser and dosing it at the same rate have the same effect as purchasing a peristaltic pump?

bertoni
07/24/2011, 05:48 PM
Well, that would reduce the amount of calcium and alkalinity being added, and it might take a lot of dilution to reduce the precipitation.

Hephalump
07/26/2011, 09:40 PM
Just wanted to say thanks: The switch to baking soda helped fix my low alk problem, and so far lowering the concentration of the kalk seems to have helped with the precipitation.

bertoni
07/26/2011, 10:38 PM
You're welcome! I'm glad the situation is improving.