Was running spa last weekend and noticed the filter pressure gauge was 10 pounds higher than when in pool mode. Pool mode is about 19 pounds and spa is around 29. The top of the filter actually visibly expands when pump is turned on in spa mode.
Had PB out today and he said that a 5 - 10 pound increase is normal in spa mode and my Hayward 60 DE filter can handle the pressure. He backwashed (which I already did on Friday) but it didn't make any difference. Spa has 2 1/2 inch pipes, 2 drains and 5 returns. Pump is 2HP Northstar.
Anyone else experience this?