Got pointed 18x42 pool all set up and went to use new intex sand filter pump this morning. Started off with backwash as instructed then moved on to rinse then to filter. Noticed that there wasn't much water movement in pool and no suction. Hubby realized he'd connected one of the hoses of the pump to the drain instead of in. Fixed it and suddenly we thought we were good until we noticed the pile of sand on bottom of pool. Could this be result of backwashing with incorrect hook up? Pump is brand new so I'm doubting it has to do with anything being cracked. I didn't notice any more additional sand to the pile despite running the pump on filter for about 4 hours.