I have no idea but I would be worried about what other metals are in the polished aluminum. If it is pure aluminum which I imagine very few things are these days I think youd be OK. As cheap as PVC and tubing is, I wouldn't take the chance myself. We use copper in our homes but copper in a tank is usually a bad thing unless you are medicating.
Do NOT use aluminum. Avoid using copper. Both leach toxins, metals and other stuff into the water. Try to stick with the old standards and you'll be ok.
I work mechanical maintenance around machinery that has (had) aluminum components that basically turn into powder underwater. We had to replace those components with stainless. Also, if you notice that public places that have fish ponds in which people like to throw pennies in usually keep the bottom clean so the pond doesnt get toxic from all the change people throw in.
Good luck.
