Plastic water containers may not be a good idea for storing water.

[Gizmo]

I use that exact container to store RO/DI water in. No problems as of yet. Maybe they are made with Bisphenol A, which everyone has seen on the news as a very nasty chemical to be ingesting. The fact is no matter what you do to store water, something "could" leech its way into your water supply. Old Silicone, dust in the air, your sig other spraying febreeze in the other room... <insert rolling eyes here> but my point is, if its not one thing its another. I'm not going to stop using that container until I see scientific proof (other than dead sperm) that it had detrimental affects on my tank. BTW, they work great with the wheels.