So, im going to start an outdoor grow this year, and i was wondering if it would be good to use old aquarium water to water them from time to time? One ever 1 or 2 weeks, after i clean my aquarium i have about 5 gallons of dirty aquarium water, which im sure is full of nutrients. Should i water my plants sometimes with this water? should i give a little bit to each plant? or alot to only a couple of them (ill only have about 5 gallons a week so i obviously cant water all my plants with alot of it). Also, how often should i water them with it?