Slime in top-off tank?

[captexas]

I have a 29g top-off tank that sits next to my sump with a power head in it hooked to a level controller that pumps fresh water into the sump when needed. Last night I went to remove the power head to try to use it on another little project and found it along with the tubing attached to it coated in a nasty clear slime! The 29g tank was used for a sump on my old tank and has some silicone from where the baffles were, but I wouldn't think the silicone would melt down into a slimy substance so I'm not sure what it could be. Anyone know what this slime is or what produces it?

[RobertG]

I have the same thing going on. I have never seen any negative affect from it. I use the can for both fresh and salt.

[NaCl_H2O]

Put some Kalk in it, that will get rid of the slime ;)