I wouldn't use any type of oil in the tank environment. I've always just used RODI. But, if you wanted something more effective, I would *think* you could use something like pool silicone lubricant.Ok thats same point I also had, plus if the heights are not good i can still change them but I should probably use some oil to get the pipes really deep without glue, am I right?
Didn't know there was such a thing (food grade) but, regular vaseline is petroleum based so, I would be leery of that.Maybe food grade vaseline?
Yup, but I wonder whether the pressure from the return pump might disconnect the return line resulting in a disastrous fountain![]()
Or, don't glue the return but, instead, use MPT and FPT fittings to screw them together. That way you can unscrew them if needed.