Diamondbrite deterioration

[pgershon]

21 year old pool. 10 years sine Diamondbrite was installed. Noticed that the walls and floor got very rough, and that Diamondbrite sand was coming off in pool vacuum (large amounts whenever robot is run). Pool had been maintained by service and when I tested levels CH was 70 and CSI was below -0.50. I suspect that plaster was damaged by this summer and perhaps prior summers of poor CH maintenance.

I am maintaining pool myself now and focusing on CSI. But my question is, is there anything I can do to smooth the Diamondbrite or otherwise restore the damage? Even to stop the continued degradation of the pool surface? I have good CSI now, but the finish is still coming off (or so it seems based on what comes off with pool vacuum.

 

[mknauss]

Once the calcium is removed from the binding plaster of the finish you can not put it back. You are most likely best to start planning for a full chip out and replaster.

 

[pgershon]

Well I got 10 years out of that finish and the next one I will maintain better.

But one question to tie everything together. I have been SLAMing my pool for 6 days now and I still have 1-2 PPM of FC loss overnight (3-4 drops of reactant). My pool looks perfectly clear though and I do not see any signs of algae. Might it be hiding in the slightly deteriorating pool surface. Anything more I can do?

 

[mknauss]

Brushing will get to the algae but also scrape off more of your finish. You are in a bit of a spot right now.

If the water is clear and your OCLT is around 1, I would suggest letting the FC come down but maintain a higher level than target range. Say 15% of CYA. See if that keeps the algae at bay that is embedded in the plaster. Treating it like black algae.