"BoyPete" wrote in message
...
Ford Prefect wrote:
I keep a couple of tropical fish tanks and was wondering if the waste
water after water changes would be benificial or harmful to garden
plants, seems a shame to flush 40l a week if it could be doing some
good in the garden instead.
Cheers,
Ford.
It's great for the garden. But, what are you doing with 40l changes a
week?? When I kept tropicals, I only did partial changes if water
parameters were off the normal. unnecessary changes will stress your
fish.

I kept tropical fish for years and I don't recall ever changing the water,
whole or partial.