I know 2 ports are used for recirculating , 2 others are used for regular in and out flow and I believe the last smaller port is for aerating but i might be wrong. Its going to be hard to run those hoses under your deck without some major rebuilding or creating a large fiberglass tub to go around the tank like a liner since thats normally what this type of tank is used for . with this tank its best to put at the transom unless u dont mind jumping over hoses.
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