We've just installed rain gutters on one side of our 30x96 ft greenhouse. The water is channeled into a 55 gallon drum, then pumped to an 1100 gal storage. The storage is opaque, and we've covered it with a dark sun-shield tarp.

We use this water for the watering (adding fertilizer as needed via dosatron) in the greenhouse. We've been using treated water from our well until we set-up this recapture.

The water in storage seems to feel somewhat slimy, in spite of our efforts to keep the storage containers in the dark. I'm concerned about the affect this will have on our plants. Is there something i can/should be using in the water to deal with this before (or while) it goes through our dosatron to the plants. Or, do i need to worry about this at all ?

When we used "house water", we also added sulphuric acid (using another dosatron) to bring the ph down from 8.3 or so into the low 7's.