Currently I have black algae in my pool and they are holding on the little cracks in the shallow side of my plaster pool. Before I purchased the house, it seems like they drained the pool or lost lots of water during winter where the water was drained from the whole shallow area of my 18K gallon pool. During winter the water penetrating into the plaster cracked the plaster so the bottom of the shallow end is quite rough. It is not bothering me but now that I have black algae it is very hard to get rid of it and looks bad.
I tried brushing with a wire brush several times but I could not get rid of it all. It might be because I did not shock it long enough and I was missing chemicals from my tf-100. I just ordered one and will shock properly now. I even tried power washer in the water to remove the algae from cracks It works but is a lot of work.
My problem is that I want to fix the plaster surface. I am considering sanding the bottom of the pool. I want to do it without draining the water. I know there are submersible sanders. They are a bit pricey though. I was wondering if anyone had any experience with any air or water driven tools to do underwater sanding. I have read a diamond blade does the trick and a wet sander will give it a nice finish.
The other alternative is to drain enough to expose the shallow end and use regular sander. I suppose the cost of the water might be around or less than a decent submersible sander. There will a downtime for the pool though.
The last option is the have the plaster applied again.
What are your opinions on this problem?
I am also considering switching to salt water system but that will be a different topic. I just wanted to state it here in case new plaster job will interfere with salt water system.
I guess I can go with vinyl instead of the plaster. I will search the forum for topics on my options but if you have something you can recommend, it will be greatly appreciated.