Just recently I have taken over looking after my 78 years old neighbour's plaster 20,000 gallon pool. It is 25+ years old and quite severly delaminated. He has to recover from major heart surgery, this may take a year or so.
There was considerable black algae growing in the pool which over the course of two weeks I have been able to remove, thanks to help and guidance from JasonLion and members of this forum. This was mainly done by maintaining shock level for about a week or so.
In a few areas, by some steps and in one area in the deepest part of the pool there are areas that I thought were black algae but are more brown in color, despite daily, sometimes twice a day, scrubbing with a wire brush, rubbing with a puck and laying pucks over the areas of what I thought was black algae they remain and indeed gets worse unless I scrub again with a wire brush. The steps might still be very deep growing algae.
My question is this, if it is rebar rusting through how quickly do we need to address the issue? The steps have area about 8 inches long and a half inch wide there are about eight of these, the deep part of the pool has an area that is about 9 inches long and 5 inches wide and is brownish in color.
My neighbour needs to conserve his monetry funds and I think would rather wait. Is this OK, or do we need to address this issue quickly? He cannot afford to replaster the whole pool. Also might anyone have an idea of the approximate cost of doing these repairs? If you do I will need to multiply that cost by 50 to 100 percent for Honolulu as every thing here is much more expensive.