WATER BUTTS! - should I empty all the 'old' water out?

[Lucycat]

ok, so we get gallons of rain here in Manchester, so our water butt is always full, but at the moment it's looking a bit slimy an d full of tiny flies.

Do I empty it and risk our garden becoming a swamp until it dries out, or is it going to be fine to use this 'old' water on my veggies?

Would be fine to use this water on your veg, assuming that you mean the veg you're growing rather than cooking! Down here in London we're all on a hosepipe ban - what I'd give to be able to go out and water our garden!

absolutely fine to use it on the garden