[It is a Sequence Dart which already has the proper seals. Trouble is I am having micro-bubble problems so I am diverting a lot of flow back into the sump instead of the tank. It I had thought about it more I would have picked a different sump design as this one can't handle the high flow. Needs more baffles and greater distance between the drains and the return pump. I may add another baffle were the flow turns the corner between the drains and return. This should help out alot.]