Was at my dad's last night, as I'm taking care of their 13,500 gallon 15'x30'x4' AG pool while they're on vacation. It has a Hayward 1 hp powerflo LX and a Purex (now pentair) triton star ST50 de filter.
Looked up the specs on the pump and filter this morning, and found a potential problem. The max flow rate on the filter is 50 gpm. The flow rates at various head loss for the pump are-
10 dhl- 86 gpm.
20 dhl- 86 gpm.
30 dhl- 75 gpm.
40 dhl- 58 gpm.
50 dhl- 27 gpm.
Unless they have a very high dhl, there pump is too powerful for their filter.
The pump and filter are immediately below the deck of the pool. All pipe is 1.5". For the suction line, a 90* elbow comes off the pool, 4' of pipe straight down the another 90* then 2' of pipe into the pump. About 3' of pipe/hose (can't remember) between the pump and filter, then 2' of pipe from the filter to the pool, a 90*, then 4' of pipe up the pool into another 90* that feeds the return in the wall.
So, suction is 6' of pipe with 2 90* elbows.
Return is 8' of pipe and 2 90* elbows.
Any guesstimate to what the DHL is?
Filter pressure reads 23 psi, however I'm not sure the gauge is working. My dad said it doesn't move much. I haven't turned off the pump and relieved the pressure to see if it's still working or not. Another possibility is he said when he broke it down to clean it (after he fired the pool store maintenance), there was no DE in it that he could see, and none in the yard by the drain hose either. Not good signs. Filter elements could be clogged or damaged from being run without DE, but there's now DE back in the pool, so I have my fingers crossed.
Anyone know what the expected PSI should be in this set up?
Oh, one more thing. There is a valve on the suction side ahead of the pump. If it turns out the flow rate is too high, can I partially close this valve to reduce flow?