Plaster Erosion


New member
Jun 23, 2008
I have a small 4000 Gallon lap pool that has been ignored somewhat over the past year. It doesn't matter too much what my test results are as of today because the damage has already been done!

I believe it is from too low ph, but the plaster is pitting in some (alot) of areas and is rough to the touch. In other areas, the plaster surface is brown or almost black in some areas. The brown areas are almost slimy to the touch. If you rub over the rough part with your fingers, the plaster will just rub right off.

Besides getting the pool water in balance, is there something I can do to remove the brown/black splotches? I've heard an acid wash might help the color, but not the roughness? or perhaps a re-plaster is in order?

Does this sound like low ph or a calcium/hardness issue?

I'm new to the site, so if this informatio is elsewhere, my apologies.
A full set of test results would be helpful. as far as the slimy patches, they sound like they might be algae.
The test results do matter because they can help us to determine what actions you should try first.