calcium

[scuba2]

Thanks for the feedback. I hace been getting close to the cal level that I want. I have been reading some of the posts on b-Ionic,and many people are saying that they have to add over the starting dose thats on the bottle. Most of them have corals in there tanks that are consuming the cal. My question is this., I am only trying to get some pink alge in my tank. I have no coral yet. my consumpition should be a lot less . Therefore It should not be so costly I believe????????. Doese cal leave the tank in other ways besides coral consumption. for example evaporation ???

[thrlride]

Calcium will only be used up in the tank through coral consumption and coralline algae growth. You could have precipitation which would lower it and I imagine if you did a lot of water changes with water that is low in calcium you would lower it that way too.

Mostly it is coralline and coral consumption though.

[Randy Holmes-Farley]

I agree.

Therefore It should not be so costly I believe????????.

Yes, that is true. The commercial two part additives are a good choice for tanks with a minimal demand. That said, the demand from coralline algae can be significant.

The only other ways that calcium leaves is via abiotic precipitation as calcium carbonate (on heaters, pumps, sand, etc) and via water changes.

[maoiwowie]

Randy...i am assuming calcium percipitates when it reaches over saturation. And this can be seen when viewing your tank as being cloudy or a thin layer of white on the water surface? But will this percipitated calcium be "redissolved" in solution when adding unsaturated salt water?

[Randy Holmes-Farley]

Randy...i am assuming calcium percipitates when it reaches over saturation. And this can be seen when viewing your tank as being cloudy or a thin layer of white on the water surface? But will this percipitated calcium be "redissolved" in solution when adding unsaturated salt water?

No, seawater at 420 ppm clacium, 2.5 meq/L alkalinity and a pH of 8.2 is already substantially supersaturated. CaCO3 will not dissolve at all under such circumstances.

That supersaturation is preserved in various ways (such as magnesium poisoning the surface of calcium carbonate crystals as they start to form) and lasts permanently in the ocean. However, in reef aquaria there are things that are constantly causing some new precipitation, such as warm objects like heaters and pump impellers that often slowly get coated even if there is no precipitation elsewhere.