Storage bucket issue

[YE||0W TA|\|G]

I keep all my pre mixed salt in a brute 40 gallon container and every few months i start seeing this junk build up at the bottom of it. I have no idea what it is.. it feels like sand paper to the touch.. I use RO/DI water so i dont think it could be this. It comes off like in paint chip form.

I have an ehiem pump that i run to move the water around so im thinking it could be this but im not sure i also have a air strip to circulate the water as well but i know it cant be that

Has anyone ever ran into this problem?
heres a pic of what im talking about, it took me 1.5 hours to clean that out with a algae scrapper! what a B@#%^!

on the reef discussion forum someone said it could be Calcium participate.. can someone help me out and explain to me what that is

http://i642.photobucket.com/albums/uu144/Yell0wTang/IMG_0531.jpg

[HighlandReefer]

Randy explains this issue in this article:

http://reefkeeping.com/issues/2005-07/rhf/index.php

From this article:

"Solid Residues Remaining After Preparing Artificial Seawater

Most salt mixes leave behind a solid residue when dissolved, although the extent to which this occurs varies from brand to brand. I use Instant Ocean and rarely clean out the 44-gallon trashcan that I mix it in, so a significant residue builds up over time (Figure 1). In preparation for this article I removed some of this solid material, and found that it could be almost completely dissolved in hydrochloric acid with lots of bubbling. This demonstrates that these solids were probably calcium carbonate (CaCO3), perhaps also containing magnesium. Pure magnesium carbonate is undersaturated in seawater (which is detailed in later sections of this article) 1 and should dissolve in marine systems, so it isn't likely to be the precipitated material, although there may be significant magnesium in the calcium carbonate.


Figure 1. The residue on the bottom of the plastic trash can that I use to mix Instant Ocean. I rarely clean it out. The solid is most likely calcium carbonate.

Based on the fact that the material exists as sheets that clearly did not arrive in the mix (as opposed to a fine powder which might have), I conclude that at least a significant fraction of this residue formed in the barrel. I cannot, however, rule out the possibility that some solid calcium or magnesium carbonate may have existed in the salt mix and was cemented together by additional precipitation of calcium carbonate during dissolution or storage.

When salt mixes are dissolved, there exist local regions where the salt concentration is very high. In those local regions, the calcium and alkalinity must also be very high. In fact, as seawater is concentrated by evaporation, there is a well-established series of minerals that precipitate as the salinity increases. In this series, calcium and magnesium carbonate are the first to precipitate, appearing at a specific gravity of about 1.140, which is about a 50% solution of salt in water.1 Such conditions may well exist on the bottom of a saltwater reservoir as the salt is dissolving."

[Jason Donohoe]

If it dissolves easily with vinegar it would confirm the calcium carbonate theory. Follow that with an ro/di rinse and you are good to go.

The build up I get at the bottom is white/grey intead of the brown you have but I also get a similar slime layer to the sides of the container.

I read a post not long ago and the general consensus was not to worry about it. I still scrub down the sides and rinse with vinegar periodically, but I'm a little bit of a perfectionist. Actually, a little bit a#$l would be more accurate. :)

[minispider]

I get it when I store mixed salt in the container for more than a week, I use reef crystals, rodi water and a pump to keep things moving in there but still get it, when I use the water I just wipe the container clean and fill it again. Mine is not as bad as yours, is just a faint brown and is not the entire container.