Hello, Im a new member, I have a question regarding a tank im setting up. I have a 75 gallon Im setting up, it had pesticide spilled in it. i disposed of the gravel however the under gravel filter and bottom of tank have residue in it. How do i clean that off? I also read you can use vinegar to remove hard water stains. i guess just rinse well??? thanks for any help, i want to get this tank going