I have a 15, 000 gallon pool, 1hp pump (abt 8 years old), new Hayward 900 filtration system with a new filter, dedicated vacuum line and a new Barracuda G3. The Barracuda stopped sucking. I had the diaphragm checked and it is good. I cleaned all the baskets and rinsed the filter and the Barracuda still wouldn't work. It also seemed that the main drain and the skimmer weren't pulling in a lot of water. Pressure on the filter gauge is between 8-10psi. I then took the filter out and turned everything back on and guess what the Barracuda works great and I have crazy suction. When I put the filter back in, the Barracuda stops working and suction goes down. Any ideas? This is driving me crazy. [/size]