Forgot to say thanks for the info, but also to ask the following
question:

The malachite green instructions said nothing about keeping a UV
filter on or off, so I left mine on. Since your message says that it
is inactivated by sunlight, does that mean that the UV filter rendered
my treatment totally useless?

Also, after it is deactivated, can the water treated with it be used
in my landscaping (you said salt wont hurt, but you weren't as
definitive about the malachite green).

Thanks!

D