Yes! Several years ago, I had fish in fish bowls which I changed weekly (long reason why they ended up in fish bowls) but I used the fish bowl water for all my plants and they loved it! It's basically very diluted fish emulsion. Now I use gray water for my indoor plants and they do just fine. It's funny but I was thinking the other day that maybe I needed to get some fish in fish bowls again just because the plants so enjoyed the water. I also use gray water outside during that growing season. Good luck! jo

I used greywater indoors w/ great results many years ago in Indiana. The so-called 7-year drought cycle we experience here in Colorado is another incentive to use greywater when/however we can.

I would just be careful that the greywater that is used is not too high in salts or other substances that will accumulate in the soil. Since you can't "flush" these items from the root zone, you have to be a little more selective.

Using aquarium water is GREAT for plants. Other not so greywater that can be used and not mentioned is old coffee, tea, and cola drinks.

I use left-over cold tea or coffee on house plants. They seem to like it.... maybe because it's acid?