I think this is exactly what is happening. Especially if you saw a pH spike when you did the add.
http://www.reefkeeping.com/issues/2005-07/rhf/#6
Great post Brew! In the section of Randy's article immediately after he speaks about supersaturation of calcium in seawater and our tanks, there is a section titled,
"Calcium Carbonate Precipitation: Low Magnesium" and another,
"Calcium Carbonate Precipitation: Elevated Temperature". There are three things that "could" occur for calcium carbonate to precipitate:
1. Normal seawater at 80°C (not likely in a tank to get a temp that high)
2. Seawater at 25°C with calcium raised to 1300 ppm (most of our tanks have calcium levels this high, this is a possibility)
3. Seawater at 25°C with the alkalinity raised to 8.2 meq/L (That is an
incredibly high level of alkalinity, 23 dKH... But like you said,
You would have needed to add the solution to a very low flow area in your system for that to have formed.
, that could have happened in a really slow flowing area of the tank, where the local alk could have been that high and the precipitation would have happened to be slowly released back into the tank looking like overnight cloudiness.
These in combination would cause calcium carbonate precipitation. That's one answer. Another is what you guys have already said, which is in the next section,
"Magnesium Hydroxide" and seems likely as well. Quoting from Randy,
"Can it form when carbonate salts are added? For example, when sodium carbonate solutions are added as part of a two-part additive system? Theoretically, yes. However, calcium carbonate is kinetically slow to precipitate even when it can do so (a well established fact that is experimentally reproduced in the preceding section), and it is anticipated that the kinetic issues that slow calcium carbonate precipitation (the need to fit ions carefully into a crystalline structure) are similar for magnesium carbonate (but not magnesium hydroxide, which is amorphous) and will slow calcium carbonate precipitation as well."
It seems to me that it is calcium carbonate precipitating slowly, or "kinetically slow to precipitate". There are so many factors going on here that could cause this cloud and it could be both calcium carb and magnesium carb. The article talks about the slow precipitation of both, and that mag carb doesn't come out of solution very easily, but settles out, as you stated
@Brew12 ...
Man, this is a strange thing to have happened
@jcs401 . I think we all agree that it isn't biological, but chemical, and these ions are super small. If you want to filter them out you would have to get a very small micron filter, in the range of 10 microns. You can purchase 10 micron socks on
Amazon (I just did to use for lanthanum chloride to reduce PO4 in a tank of mine). Using regular socks won't capture the small ions.
Turn your skimmer to as wet as you can, put as much filtering material as you can in the sump where water enters and right before the return and see if it helps. I don't think it will help to test alkalinity or calcium levels at this point, since there are ions of calcium and carbonate (and probably magnesium as well) that will just dissolve in the vial. Just wait it out, doing a WC won't help unless you do a 100% WC and that would be more harmful. If it is still cloudy tomorrow then I would take active measures, but doing something now will probably just make it worse... This is all just opinion, I'm not a chemist. I think that you happened to be one of the very rare instances that a precipitation event like this happens, but it did..
:mad:
