HI all. We've got a 70 gallon bowfront tank that's been set up since June. When I do my water changes I was wondering if the aquarium water is safe to use on my houseplants, or in the garden (come summertime anyway) Especially when I vacuum the gravel and get a lot of the "material" from the bottom. My husband says that it's probably too acidic. Seems to me it'd be good fertilizer. Any ideas? Thanks!