My pool and equipment have been installed for nearly 2 years. Lately, I've noticed a problem where, my filter pressure gauge reads high, so I check to make sure all the return valves are open (husband sometimes monkeys with things!), and then I can cut the pump completely off, wait a minute, cut it back on, and the pressure reads at least 10 less. Is this a good indication that the gauge is going bad? I can't think of anything else that could be causing the pressure to go up on the filter. Is there anything else I should check?