11-05-2009, 07:04 PM
Join Date: Dec 2007
Location: Near San Francisco
| | Re: Rain water
I allow a couple of storms to wash the roof, then collect and use the rain water in season. It does start to soften the water in the tanks, as it dilutes the minerals. Any tanks that should not be softened (Lake Tanganyikan and brackish water tanks) get some minerals and salt added that keeps them where they ought to be.
Careful also if the roof is toxic. For example, a rain collection system that has a lot of copper is not good for shrimp and snails. (I remember a post from someone with copper sheeting over the roof.)
Take care when collecting the water that it does not stand too long and start to grow mosquitoes. Feed the mosquito larvae to the fish, of course, but better to use the collected water quickly or cover it so you are not breeding the little pests.