[mike31154]

The return PVC lines for my skimmer are a combination of threaded fittings and press fit with a little teflon tape, no solvent or glue whatsoever. Been that way for two years, no problem. The 'pressure' of the flow is so low through those lines, it's unlikely to ever leak unless I mess with it. A little salt creep is all I've had and I simply wipe that up from time to time. Not sure I'd do that with a lengthy drain or return, but I've found that new PVC and ABS material fits together very snugly if you push and twist enough. The only concern would be vibration from a return pump or something similar, which may shake things loose over time, but you've glued yours and even with the 'improper' solvent, you'll likely be ok. The silicone recommendation around the outside sounds like a good idea rather than starting from scratch.