We bought a house with a Sta-Rite System 2 Modular Media Filter. All the owners manuals for the pool came with the house except this one. I was able to download it online but I have no idea what the "start up pressure" for this pump was since it was already installed when we got the house. The filter was cleaned when we had the pool drained and refilled the first week of March of this year. I read that we are supposed to clean the filter "when the pressure gauge reading increases 10 PSI over the start-up pressure." So how am I supposed to know what the startup pressure is? If there is no way for me to know, what pressure do I clean the pump at?