My husband picked up a shower filter for me to put inline with the hose so I don't have to fill buckets for offgassing every day. When I looked up what the filter media is it says it uses, "clorgon and kdf". KDF is a mixture of copper and zinc. I've read elsewhere that copper isn't so much a problem if the water is just flowing through it once, that it becomes much more of a problem when it sits in the tank, but I wasn't sure if this was okay to use since it's basically ultra fine particles of it that the water passes through to remove chlorine.
P.S. I know they make inline hose filters, which are actually what I asked him to get. Does anyone know what the filtration media used in those are? I plan on getting one of those next, just wondering if this would be okay in the meantime.
Since, I posted that, I've been using the filter with no problems, though I should probably be careful to do water changes so there isn't accumulation of the copper/zinc.
I would love to just use rainwater, but I live in Phoenix. I collect rainwater, but it isn't anywhere near enough (it's so dry and hot that I'm losing about an inch a day right now to evaporation and we've gotten about 5 inches of rain at my house for all of 2011. On a side note, one of the things that really drew me to aquaponics was the claims that it uses so much less water than traditional gardening, that's absolutely not been my experience. Maybe in a greenhouse, but out here you can't have a greenhouse unless you have cooling systems in place (which either use lots of power or a little power and a fair bit of water).
Oh yeah, use blingy reflective materials to cool surfaces.