2" overflow plumbing

[sphelps]

You should really try and match your overflow to your return flow. Well too bigger is better than too small if the plumbing is too big it will be nosier. Unless your'e running a large return pump I would simply get a new 1.5" bulkhead that fits in the same hole. The bulkheads I use require the same hole for both 1.5" and 2". Or you could install bushings in the bulkhead to reduce the size.

This way you'll also be more familiar with the plumbing, and your standpipe won't take up as much space in the overflow and it should run quieter.