Sand filter choosing

Nov 11, 2015
14
CA
I have a DE filter and trying to clean a green pool. I had to wash and precoat the filter twice a day because it got dirty and stopped flowing quickly. I'm thinking about getting a new sand filter. My in ground pool has about 30000 gallons water and the pump is AO Smith, 2HP. Right now I'm looking at Pentair Triton 2 and Hayward Pro series. Can somebody help me choose the filter? I appreciate your help.
 
First, I will answer your specific question. The WhisperFlo WFE-28 is a very high performance pump. It can do very high flow rates at lower head, and it can generate high pressure (up to about 37 psi).

It will do 120 gpm at 40 feet of head and about 45 gpm at 85 feet of head.

My opinion is that you should have about 1 square foot of filter surface area for every 15 to 20 gpm of flow at the lower end of the head curve (low resistance, high flow).

120/15 = 8 square feet. 120/20 = 6 square feet. The average is about 7 square feet.

The Triton II TR-140 has 7.06 square feet of sand surface area.

If you’re going to keep your existing pump, I would recommend the TR140.
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Now, the question is do you really need such a big pump?

My opinion is that you almost definitely do not need such a big pump. Unless there is a reason you need such high flow, you would probably be better off getting a much smaller pump or a variable speed pump.

If it’s an old pump and your electrical rates are high, I think that it’s an easy answer, replace the pump.

It it’s a newer pump and your electrical rates are low, then it’s much harder to justify replacing the pump.

How old is the pump and what are your electrical rates?
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The next question is do you really need a new filter? A DE filter works quite well as long as it’s sized, operated and maintained properly.

Which specific filter do you have and how old is it?
 
First, I will answer your specific question. The WhisperFlo WFE-28 is a very high performance pump. It can do very high flow rates at lower head, and it can generate high pressure (up to about 37 psi).

It will do 120 gpm at 40 feet of head and about 45 gpm at 85 feet of head.

My opinion is that you should have about 1 square foot of filter surface area for every 15 to 20 gpm of flow at the lower end of the head curve (low resistance, high flow).

120/15 = 8 square feet. 120/20 = 6 square feet. The average is about 7 square feet.

The Triton II TR-140 has 7.06 square feet of sand surface area.

If you’re going to keep your existing pump, I would recommend the TR140.
______________________________________

Now, the question is do you really need such a big pump?

My opinion is that you almost definitely do not need such a big pump. Unless there is a reason you need such high flow, you would probably be better off getting a much smaller pump or a variable speed pump.

If it’s an old pump and your electrical rates are high, I think that it’s an easy answer, replace the pump.

It it’s a newer pump and your electrical rates are low, then it’s much harder to justify replacing the pump.

How old is the pump and what are your electrical rates?
_____________________________________________________

The next question is do you really need a new filter? A DE filter works quite well as long as it’s sized, operated and maintained properly.

Which specific filter do you have and how old is it?

I really appreciated your help. I bought the house 5 months ago. It was built in 1989. Previous owner only had the house for 1 year so he did not know the history about the pool. I'm assuming the pump and filter were made in 1989 or later? The filter I have is a PLDE 48. I searched online, Pentair has a similar one with the same model number, but my filter is STA RITE with 96 gpm max flow rate and 48sqft filtration area. The reason I'm thinking about getting a new filter is there's no backwash valve. I have to take the filter out and use a garden hose wash it and the drain goes to the street. Whenever I wash the filter, I get a messy white street. My neighbors complained A LOT. I'm thinking about upgrading the pool by myself because the heater isn't working, the check valve is leaking, and it's really hard to buy a exactly same filter module. When I just purchased the house, the owner told me the filter was too old and I needed to get a new one. I spent almost 300 dollars on the filter because it's old and only 3 or 5 online stores still have it. Also the lock ring's cracked. Even the water is crystal clear and the filter is clean and pre coated, it only lasts for 2 week. I have to clean the filter and street every two weeks. I'm tired about it. The workers who built the pool was lazy. There's no union on it and they use 3 inches PVC pipe. I have to find some adapters so that I can install my new sand filter. I know DE filters work the best. I just want a filter with minimum maintenance. I just ordered a Heyward Proseries High Rate Sand Filter, model number is S310T2. I wish it would fit with the pump. I don't wanna get a new pump right now. It'll cost a lot. The website says the filtration area is 1-23 sqft but another pool supply website says it's only 5 sqft but the flow rating is 98 GPM. I live in CA, everything is expensive. So I only turn the pump on 3 to 4 hours every day. As long as the water is not green and cloudy, I'm happy with it. I don't use the pool a lot, but if the water is green, I'll get a ticket from the city. It's about 300 dollars EVERY DAY. Thanks again.
 
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