Sand in pool

They make underwater polishing equipment (not even close to cheap) for that purpose.

I thought I'd mentioned earlier, maybe I dreamed it, or it's the fatigue & allergy meds, but throw away that SS brush. It's slowly damaging your finish (maybe even causing "sand"). Get a nice high quality nylon brush. SS brushes are too aggressive for nice finishes. Older pools with a bad surface and algae? Go for it. Otherwise no.

I mostly use a nylon brush for routine cleaning, but I have the SS brush for the occasional heavier need. The surface is at least 7 years old and a little rough in spots. The previous owner said refinishing after 10 - 12 years would not be unexpected. Don't know if that's right or not. If so, I'd expect to refinish in 3 - 5 years. I'd probably want to do it anyway to fix the "pockets" that in in floor pop-ups are in.

Really depends on care. Some folks need refinishing after 7 years, some go 20+ years.

When you replaster, make sure your contractor uses the infloor collar extensions to raise the heads up level with the new plaster.

Would it be unreasonable to expect a refinisher to grind down around the in floor fittings and main drain., etc. so the new finish is flat ?

When we replaster a pool we set a new main drain cover and use the infloor collar extensions to keep things flush. Other items, like lights and return fittings, we chip out around those so we can bring the plaster back flush with the fitting.

Thanks. I'll keep an open mind. I suppose if I want it done a certain way that is not standard practice, it becomes a cost/ benefit trade off.

In the past we have chipped out around the infloor heads to bring the plaster flush, by we have to go back about 2' around each one to do it well. Not worth it when the collar extensions have no effect on the performance.