Sand in pool

[PoolDoc]

It's really quartz crystals (i.e. sand) but is includes green and blue particles that are the same color as the "specks" in the finish. I

That pretty much narrows it down, to dissolved pool surface.

If you maintain your water, the rate of deterioration will slow, but won't immediately end. The reason is, aggressive water conditions penetrate into the finish, weakening the matrix that holds the quartz particles. Where the matrix dissolves completely, the particles are immediately released. But where the matrix is only weakened, it may be some time before those particles shed.

FWIW, I'm pretty sure some of those surfaces can be refinished merely by regrinding them -- if the remaining surface material is thick enough. Marin would probably be able to either confirm or correct this, and possibly point you in the direction to carry it out, if it's possible.

[nefretrameses]

Thanks Doc & Greg.

It makes sense that aggressive water is the root cause. Hopefully the damage isn't "fatal". I'll keep brushing and maintaining my water balance.

Our swim season will end sometime in mid or late October. Would it be of any benefit to raise pH or another factor so my SI is even more positive during the winter? The pool stays open.

[Marin]

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.

[nefretrameses]

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.

[Marin]

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.

[nefretrameses]

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 ?

[Marin]

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.