matt_trace

hi all i visited my LFS yesterday (not my usual one) asked if i could have some RO water which is what i usually bye and he said he didnt sell, it so i asked him if he brought it in for his fish and he said no, so upon asking him what he puts his fish in he told me he leaves tap water to stand for a few days which takes the chlorine out of it and then its as good as ro water?? is this correct or is he talking rubbish, surly if this was the case there would be no need for us all to be bying ro water we could all use tap water if we let it stand a few days, all his fish seemed to be happy altho i didnt buy any based on what he had told me about his water so wanted to make sure if his way is wrong or right?

TedsTank

Sitting for a couple of days does remove the chlorine but that is all. R/O water is also soft and neutral in pH...it has no buffering. He is quite wrong or misinformed. Ask him for his water parameters. this fish aren't there for long (usually) so the fish may be fine but maybe not for a lifetime as our goals are.

matt_trace

ahhh i see ok thanks i shall continue with ro water then
thanks

lew2000

Also most municipal water systems today use chloramine (not only in the US)not chlorine. Chloramine is does not outgas as readily - most waste treatment sites state that 7-10days is required for outgassing to ocurr. You also still have the issue that some heavy metals are usually present in tap water (levels that are within EPA tolerences) - which should be bound up with treatment.