Home Depot Sump?

[JonT]

Originally Posted by jphong

It will be for the RO reservoir only so not salt there, plus its for freshwater setups I have. But even without the salt Im sure it will rust in the long run sitting in the reservoir. I also saw some beads of glue/bonding agent on the base of the pump that made me weary to buy it.

With or without salt...

Water is the most solvent liquid on the planet. It tries to absorb everything. So, take your RO water, that you have removed all dissolved solids from (0 TDS right?) and now you have a liquid that is ready to absorb everything it can.

If you think I am full of it... Take a small piece of your live rock, and toss it in your holding tub. Wait a month or so, then go look. I bet you have a bunch of mush around the rock (if the rock is even left). The water is taking up the calcium, and other elements from the rock.