Rain barrels - keeping water from stagnating
Now that we have some makeshift rain barrels set up, we've gotten rain and haven't had to empty the rain barrels on our plants (Murphy's Law!). I have the water covered with lids but... will it get stagnant? Any tips on how to store the water for several weeks?
I've read mixed info. Some say to add 1/4 c. bleach to it every few days, as that'll evaporate daily and won't hurt the plants. Some say to put a goldfish or 2 in the barrels, but what if there isn't enough algae in there for them to eat?