Is my sand filter sized right?

[TheGoose]

Pool Info-IG Gunite approx. 18,000 gallons. Recently installed Hayward Swimpure SWCG (up to 40,000 gal)
1-HP Pentair Whisper Flo and Tagelus 60D Sand Filter.

I have been battling water cloudiness for awhile now. Setting aside all the chemistry aspects of the pool for the temporary time being, do you think my filter/pump combo is right or wrong? I bought and installed both myself about 2006, and then this year replaced the bearings in my motor.

It seems that even when my pool chemistry is good, and the water has a good color, there is always a cloudiness or blur in the water. I changed my sand earlier this summer, and it helped some. I'm on the verge of going back to a DE Filter now that my skimmers are operational (long story). The filter shows delta-P over time, as you would expect, and when I backwash I do get the typical dirty looking backwash water. I am almost certain than when I backwash I am losing sand, and I noticed that when I changed the sand that the level was a little low. I am trying to keep my backwashes down to a minimum.

Open to suggestions and comments.

[BigDave]

Is your pump 1 or 2 speed? Is it an Up rated or Full rated model?

[PoolDoc]

The maximum LISTED flow rate for a TA60 is 60GPM; the maximum flow rate for GOOD effluent water quality is 35 - 40 GPM. When you run the filter at the LISTED flow rate or higher, you will force fine debris THROUGH the filter and back into the pool. But, at 30 GPM, a sand filter with proper filter sand will produce water clarity close to what a DE filter can achieve.

A 1HP Whisperflo will generate somewhere between 60 & 80 GPM on a typical layout with 2" pipe. If you replace the pump internals with the parts from the 1/2 or 3/4 HP models, you will lower your flow, lower your electrical use per hour of operation, and improve the quality of water leaving the pump.

On an 18,000 gallon pool, operating at 35 GPM, you'd need to run your pump at least 8 hours.

[BigDave]

What parts would need to be changed? Impeller, Volute, Motor? Just Curious.

[PoolDoc]

See https://www.pentairpartners.com/prod...mpParts_US.pdf , page 458 and 459

It appears that you might be able to change only the seal (#16) and impeller #(28). It looks like the diffuser (#13) is the same in all of the pumps below 3HP.

[TheGoose]

Hey guys thanks for the great replys. I definitely think that I am under-filtering my water. My original pump was a 1.5 HP with a swim-quip DE filter of approx. the same size (physical size). When I had the DE filter it was a real pain because my skimmers were non-functional at the time and I could only use the main drain. I had to load the filter by popping the basket lid off the pump, washing the DE into the suction piping with a water hose, and then re-starting (and priming) the pump. I had to do this 5-6 times to get all the DE in. The whole reason for switching to the sand filter was to avoid this problem (plus the original pump/tank were 20+ years old).

My original skimmer piping was the white flexible PVC, which collapsed and was unusable. I think that putting chlorine tablets in the skimmer baskets had some type of effect on the skimmer piping. The material was just ate up from the inside. I had them fixed last summer, they had to dig under the deck to do the job. At first I thought we would have to cut the deck around the skimmers out but they were able to dig under the deck. That made a huge difference in the way the pool operated. Imagine having to hand-skim all the leaves etc. out of the pool and only using the main drain. Could've kicked myself in the butt for waiting so long to get them fixed but I had so many other things wrong with the pool that it just got pushed back.

My pump is a straight up 1-HP, no dual speed. Since installing my SWCG a few weeks ago my water is looking much, much better, but I can still tell that the clarity is not where it should be. I don't know why I had such a hard time keeping chlorine in the pool but since installing the SWCG my water stays blue and I no longer have those little algae clingers in the corners etc. That seemed like the battle that would never end.

I'm thinking about switching back to DE. I don't mind the occassional cleaning or loading the filter every 2-3 weeks if it means my water will look better with less effort.

Thanks for all your helpful input, I appreciate the responses.