I use bleach at the rate of 1 tsp per gallon in a hose end sprayer, wet down
the surface I'm trying to clean and then brush it off. On my twinwall I use
a soft cloth, and have had no damage, on teh walkways and benches and walls
I use a plastic scrub brush. Rinse again with the bleach from the dial n
spray and I'm done.

No, I don't try to avoid the plants when I do this. No, I don't kill them.
I just move them as needed so I can get to the surface I intend to clean so
I don't elbow them off the bench. Yes, they do get wet. If I feel guilty
about thisI hose them off after I'm done, but really I don't feel guilty
very often. *G*. Yes I try not to get my pleurothallids wet. everything
else is treated as above.

K Barrett
"dusty" wrote in message
s.com...
I know this isn't an orchid question but it's related I think.
I'm asking before trying something.
How can you clean algae off of fiberglass without damaging it?
Would bleach work?
If not how about one of those bath room tile sprays.