My filter typically runs at a pressure of around 14 on the gauge. It hardly ever climbs because I don't have much in the way of debris that makes its way into the pool. Today I noticed that the pressure is sitting at 12 or slightly under. I had a heavy swimmer load of kids and I wasn't home. They were supervised but I have know way of knowing if something got sucked down in to the floor drain. I checked the skimmer and all was well there. I did notice a couple pieces of plastic (looked like sliced cheese wrappers) floating in the pool that I netted out. I didn't notice anything lodged on the outside of the drain when I was brushing earlier, but I'm going to go look again just to make sure.
Would something lodged in the floor drain affect the pressure by making it go down or up at the filter? I would think that a blockage on the suction side would have a lowering affect, but I'm not sure. It may be nothing, but might be useful info to have for future reference none the less.