Finally got around to cleaning my filters a couple of weeks ago. They were pretty bad. However, after about of hour of spraying with a garden hose, they are now clean. My question is this....why didn't the pressure on my filter gauge ever rise to indicate they were dirty (pool was finished last June), and when I put it all back together the gauge never dropped in pressure (or at least VERY little)? Do I have a bad pressure gauge? Should I call the repair guy? The pressure does drop from around 20 psi to 5 or so when I switch from high speed to low speed.