In article , James
Williams writes
I am trying to control stubborn algae by darkening my tank, I have
the light off and tinfoil around the sides. How long should I expect it
to take? Does it really have to be that dark? Is the few minutes I have
the lights on to feed the fish a problem?

This is the third day and so far it doesn't look like there's any
change.

When I did this some years ago, I was advised to block out ALL the
light. Use very thick paper and make sure you paper over all cracks.
Don't unwrap the tank for at least three days. Your fish will be fine,
so don't worry about feeding them. Leave the lights off too.

HTH

--
Alan Silver