"Mike Stevenson" wrote...
I have read that ordinary cow's milk, diluted into the water supply,
has
anti-fungal and anti-algae properties. If you have some way of
introducing
this into your tubing it could help retard the growth of future
algae
build-up.

I had a friend who used this solution on several houseplants that
she'd overwatered and had algae growing on the soil... One died, and
she had to cut back the other two and wash a lot of the soil off the
roots so she could repot with as much 'fresh' potting soil as
possible. Seemed the milk soured and introduced even more problems to
her plants. Eventually the two survivors recovered fully, but you
might want to think twice before using milk around your plants.

Shelly