Ya,. I'm wondering about the plugs too. Water will get in them. Not good.
Also, GREAT idea on the stoppers for the OM-4 returns. I was extremely carefull not to get sand in my loop. Then, when tank was full, and I went to fire the loop up, Soon as I opened the shutoff's. Each outlet gulped its air out and took in a big breath of water and SAND. Had to take it apart and clean. I suggest fill the inlet first, turn OM-4 on, and start pump. then open the outlet shutoff's and use the pump to purge the sand out. The pump should push the plug out too
