Last year we installed a new gunnite Gal 25K in ground pool with a waterfall in SE PA. We bought a Merlin safety cover that was dark in color, and mesh. We got pretty many leaves and worms in it along a small gap on the waterfall side. We just opened it today and hit it with 10 Gals of 12.5% Bleach. In 8 hours the water is mostly blue and I raked out most of the leaves. I do notice there is a ring where the water level was all winter (we have a side drain about 16" below the tiles). Will this work it's way out when I put the robot in (Dauphin d6)? Also the top steps, that were outside of the water all winter seem to have faint cracks in them. Is this something the PB will/should fix? Should it be a warranty issue?