Among my various issues with the pool, the big looming issue I might have is the plaster (the pool is ~25k gallons, gunite/plaster pool). The pool company I use on occasion believes the plaster might be original to the pool, which is prob at least 20 years old, and while it's held up well, it can't last forever. They seemed to indicate that I would have to re-surface the pool no later than next spring. They estimated that its around a ~$5k job, ballpark, for standard white plaster.
Since that's a huge sum to spend, I'm wondering if maybe I can delay this job a few years by patching (using e-z patch or an equivalent, underwater application patch). The 2 pics I've attached show probably the 2 worst areas, both in the shallow end (one is a pic of the stairs). There are other areas where the gunite is showing through, but not as many areas concentrated in a small space as in these 2 pics. The white/blue is just a reflection of the sky, but the brown mottled patches are definitely there (it looks worse in the pics than in reality; doesnt appear to be algae, just discoloration). The one dark brown, round spot is sort of weird; when I pulled the winter cover off, there was a mass which looked like a dirty tennis ball, but after my pool vac ran it over all that was left was this rust colored stain. Maybe a piece of metal which fell in and corroded all winter?
So anyway, I don't fully trust the gloom and doom that the pool company is telling me, since it's in their interest to redo the pool plaster. I'm not losing much, if any water, and no large areas of the plaster are falling or peeling off (the gunite showed through about the same last year). The only issues I can tell are cosmetic, and that our Pool Rover has about a teaspoon of sand every time it cleans the pool (which I assume is small pieces of plaster). Doesnt seem severe enough to justify spending thousands of dollars, especially if some e-z patch will make things look better for a while.
Any thoughts? Is e-z patch going to do what I'm hoping it will? I only plan on patching where the gunite is showing through; the mottled look is widespread, and I assume can't be corrected unless I want to paint or resurface the pool.