is not really RO water
Of course it's an RO machine, but "real" RO's like used for kidney dialysis is exceptionally pure water
, so pure that it will of course dissolve most anything, including your aluminum
water tank. Water is the universal solvent. Watermaker
water is of course good for drinking, but it is not so pure that it readily dissolves aluminum
any more than regular tap water does.
UV light won't work
, I looked into it. Reason UV light will not penetrate water very far at all, its absorbed. Works great in a pipe of course and would work
if you have many light sources, then of course you have the baffles to deal with.
It would sterilize an empty tank if you could deal with the baffles though.
Only real way to deal with an aluminum tank that I have found, is to replace it with a plastic one, for me though that is major surgery on the boat