Cement and joint grout is coming loose around steps. Is there a good vac i can use to suck out all the sand type material. Manual one that attaches to my standard filter doesn't suck up the sand. I do have the Polaris 280 but it's needs to be looked at and i know it will not pick up stuff that granular. I was looking at vacs like the one in the image. Anyone use something like this for inground pools?