Well, at least I can be pretty sure I haven't been putting a bunch of copper into my tank with distilled. It certainly does sound like RO/DI is the way to go, though. Perhaps I'll do a little internet shopping over the weekend.
Why RO/DI? Why not just RO or just DI?
- Thread starter mhhauser
- Start date
Right--there is nothing purer than DI. We use the combination of RO with DI just to extend the life of the expensive DI resin by removing the bulk of the contaminants with the long lasting RO stage and polishing with the DI. I bet the DI water you buy has gone through the RO too as the manufacturer wants to make a profit. 
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