With the 400 gallon tank nearly set up, and almost ready to fill (the actual process will take place this coming Sunday, when I can be sure of having plenty of help), the wife has decided that we're going to refinish some of our smaller, older tanks one at a time. We've watched several youtube videos on the subject, as we've never tried refinishing one before, and several advise to use a product called "Plastix" as a polishing agent, after sanding. What none of them say is how to remove the chemical residue after polishing. I don't want the chemicals inside my tanks to poison fish. Has anyone used this product before? If so, do you have any advice as to how to remove it completely when finished?