No pressure on 2.5 hp filter pump

Just got a baquapure 2600 200 lb sand filter with 2.5 hp pump installed as part of above ground pool package. The pump has a high and low setting, and the installer told me that I would rarely, if ever, need to run the pump on high, explaining that it would save on electricity. The pool is an 18' round with about 8620 gallon capacity. Anyway on low speed, I get 0 on the pressure reading. I initially thought the gauge was bad, but when the pump is bumped up to high, it runs at about 8 lbs pressure. On low speed there is good circulation, and quite a bit of flow from the return jet. Called the pool store and salesman explained this was normal , since the pool was just filled and there was basically nothing to remove or filter yet, and it would gradually increase with usage. I looked at their display pool setup with this filter, and noticed that theirs on low speed was reading 5 lbs, and about 15 lbs on high.


Am I just being overly paranoid? or is there a problem ?

thanks


Bob P.
pool newby

If you have flow, low pressure is good. As pressure inside the filter increases, flow through it decreases. The pressure will increase as the filter gets dirty and it is harder to push water through it. On low speed, I have seen systems NEVER have an increase in pressure on the low-speed setting and the only way to know that the filter needs cleaning is to put the filter-pump on high speed to see if the pressure has increased +/- 10# over a clean reading.