Assembly & Re-Assembly:- When recommissioning your pool after winterisation or service there is a saying “Cleanliness is next to Godliness”. If assembling any pipework unions, valves etc in fact any O-ring making a water seal it is well worth cleaning and applying a light smear of water pressure grease or similar to the seal surface. A bit around the screw threads can also help. Silicone Grease
When tightening the grease will allow the O-ring to have a bit a slip and seat correctly. The grease on the threads will also help from the point of view of tightening, a correctly fitting union with both faces parallel should only need to be hand tightened, jumping up and down on the joint with plumbers pipe grips should be avoided at all costs.
Poorly aligned union joints must be avoided as pipework under extreme stress has been known to crack. Joints might well seal with the aid of the plumbers grips but be a flood waiting to happen. The in and output ports on pump have also been know to crack when their own union joints have been misaligned and placed under stress they were never designed to endure.
Filter O-rings:- Going with the “Cleanliness is next to Godliness” theme when assembling and reassembling O-ring and joint surfaces on sand filters it is always wise to ensure no glass or sand media whatsoever is contaminating any seal surface. Damage can be caused in the form of tiny cuts needing seals to be replaced. Inspect the seal, clean with a bit of soapy water to remove old grease, clean the mating surfaces and apply a light smear of grease before final connection.
Back Pressure to high:- A major cause of back pressure being to high can be down to an air leak on the suction side of the pump, shown as a higher than normal reading on the filter pressure gauge. Air can be drawn in and pushed through the pipework system and collect within the filter itself severely reducing water flow. If you have an above ground pump and filter system and in some severe cases with below water line installations it can actually cause the pump to lose prime and cause damage if not found in time. Another symptom is a noticeable loss of pressure at the pool jets.