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Thread: 2 speed vs 1 speed pump/filter

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    2 speed vs 1 speed pump/filter

    Hello to all. I am considering a 1 speed or 2 speed whisperflo (1.5 HP uprated) and I am torn with regard to which one would work out best in my situation. The pool….if it is ever finished will be 34K gallons with no spa or waterfall. The cost of electricity in our area is not high but I will take all the savings I can get. The main reason that I am considering the 2 speed is for the winter months. We are hoping to be able to leave the pool open in the winter. We have an Autopilot that has a freeze guard, but I was wondering if it would be better to simply run the pump 24/7 on low speed during the winter months and not worry about the temps outside or the equipment cycling on and off. I am in OKC and the temps can get pretty cold. We have been in the low 20’s several nights this week and would guess the water temps would be in the 40’s. PB doesn’t see much benefit in a 2 speed pump and says low speed is practically useless. The cost difference is about $150 for the 2 speed. Also, PB has offered to upgrade the Pentair SD80 filter to the Pentair TA100 for $200. Is the larger filter worth the cost? The Pentair rep says the SD80 is the filter recommended for the pumps we are considering. Any thoughts would be appreciated?
    inground liner Grecian "L"
    34000 gallons
    1 HP whisperflo, TA100 sand filter
    Autopilot digital SWG, SC-60 cell
    Hayward Colorlogic LED lights

  2. Back To Top    #2
    JasonLion's Avatar
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    Given no spa or water features, I would go with either a two speed 1 HP or the high efficiency single speed 3/4 HP WhisperFlo. The 1.5 HP is going to be way too much for the filter and a waste of electricity on high speed and probably not strong enough to vacuum well on low speed. Pool builders almost always put in too large of a pump. They want the buyer to see some real water movement when they first get the pool and then are gone before you get the electrical bill.

    With a freeze protection thermostat there isn't really any point in leaving the pump on 24/7. Pools don't need much circulation in the winter except to prevent freezing and the thermostat will take care of preventing freezing just fine. This is a good use of low speed. It doesn't take a whole lot of water movement to prevent freezing.

    That filter is fine, particularly with a smaller pump, but if you got a larger filter it would reduce maintenance just a little and keep the water just slightly clearer. The general consensus around here is to get a smaller pump and larger filter than the builders usually recommend. The smaller pump will save a huge amount on electricity, the larger filter makes a more subtile difference.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  3. Back To Top    #3
    I am afraid that I was getting all mixed up about full rated vs up rated. The pumps in my original post (WFDS-4 and WFE-26) were actually 1.5HP. Glad I asked for help because I almost placed the order yesterday…yikes! So if the fog has lifted, the ¾ HP whisperflo (WFE-3 or WFE-24) are actually 1.25 HP pumps. If that is true and the 1.25 HP is not a peak HP, then that would help me get over my issue of having a pump labeled ¾ HP on such a large pool. It also may take the two speed pump out of the equation since the 1HP two speed is only available in 115V making it terribly inefficient on high speed and you have already pointed out that the 1.5 HP is too big. I will have a dedicated suction line for a cleaner although we will be using a robot for now. I want enough power to be able to have a Kreepy Krawly in the future. I have an extra $200 in the contract and the smaller whisperflo should be a about a wash with the 1.5 HP Superflo. Would you say the larger filter is worth the $200 or should I keep the SD-80? Thanks again!
    inground liner Grecian "L"
    34000 gallons
    1 HP whisperflo, TA100 sand filter
    Autopilot digital SWG, SC-60 cell
    Hayward Colorlogic LED lights

  4. Back To Top    #4
    JasonLion's Avatar
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    For the single speed pump I was thinking of the WFE-3 or WFE-24 (which are really exactly the same except for the name plate). Four the two speed I was thinking of the WFDS-4, which is 230V. The WFE-3 has the special high efficiency motor, which means it moves more water per watt than most other pool pumps of the same size. Even so, the WFDS-4 would be more efficient still on low speed, but noticeably worse on high speed (which would be required in various situations such as vacuuming).

    HP ratings are crazy and difficult to compare. The only directly comparable number is the brake horsepower, which is the listed HP times the service factor (SF). Max/full/up rated are just different ways of hinting at what the SF is (which are not used in any way that can be directly compared between manufacturers/models).

    The value of the larger filter in dollars depends on personal factors. A larger filter will reduce the frequency of backwashing and increase the overall efficiency of your system, but both of those will be small differences. I find that having the larger filter is worth it for me, as do many others here, but it really all depends on how you feel about money and backwashing.

    The dual speed pumps on low speed would probably not be enough to work with the Kreepy Krauly. Any of the single speed pumps mentioned or any of the dual speed pumps on high speed will be fine with the Kreepy Krauly.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  5. Back To Top    #5
    Thanks for the information. Since we will have a salt system and I don't really want to go with a DE or cartridge filter, minimizing the backwashing might not be a bad thing.
    inground liner Grecian "L"
    34000 gallons
    1 HP whisperflo, TA100 sand filter
    Autopilot digital SWG, SC-60 cell
    Hayward Colorlogic LED lights

  6. Back To Top    #6
    Would plumbing play a role in pump selection? PB installed 1.5" pipes and a pump vendor basically told me that PB didn't know what he was doing. Piping should have been minimum 2" and the 1.5" limits me to 40 GPM. I have the main drain and two skimmers on the suction side. For returns I have six wall returns/two buddy seat returns/two step returns but I believe each group ties together at some point i.e. one valve each for wall/seat/steps. HELP!!!!!
    inground liner Grecian "L"
    34000 gallons
    1 HP whisperflo, TA100 sand filter
    Autopilot digital SWG, SC-60 cell
    Hayward Colorlogic LED lights

  7. Back To Top    #7
    mas985's Avatar
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    Quote Originally Posted by rockyboy
    Thanks for the information. Since we will have a salt system and I don't really want to go with a DE or cartridge filter, minimizing the backwashing might not be a bad thing.
    With a sand filter you will be backwashing more often than the others so I am not sure I understand why you don't want a DE or cartridge filter.

    Next, 1.5" does not "limit" flow rates in any way. Water will flow at what ever rate a pump can push it through. There are recommendations which suggest that you should not exceed certain flow rates to avoid water hammer damage to the plumbing. For 1.5" pipe, it is recommended to keep flow rates below 56 GPM but this can be easily exceeded with a large pump so that is another reason for using lower HP pumps.

    1.5" pipe is pretty small by today's standards and most builders use 2" & 2.5". However, if he put in multiple runs from the pool to pad, then all is not lost. The flow rate is split between the runs so any one pipe has less than the full rate flow. Do you know how many suction and return line you have from the pad to the pool?

    It sounds as though the pipes are already installed so your only option may be to go with as small a pump as possible. Two speed or variable speed would allow you run on low most if not all of the time.
    Mark
    Hydraulics 101; Pump Ed 101; Pump and Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, 1/2 HP 2sp pump, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

  8. Back To Top    #8
    Never considered DE but I did think about a cartridge. I have read quite a bit about all three on this forum and the opinions are strong and varied. In my set up, I am going to go with a larger sand filter (TA100) which should cut back quite a bit on backwashing (600 lbs of sand vs 350 lbs). Neighbor has exact same pool with SD80 and it looked good all summer. Not sure I could tell the difference in the clarity between the sand/cartridge and if I could, I don't know if it would be worth the extra maintenance and cost at replacement time, not to mention the initial cost. Or would it?

    I just got off the phone with PB and he stands by his design. Here is what I will have:

    Suction Side:
    two skimmers with their own valve at the pad
    dual main drains (single line) with valve at the pad
    dedicated suction line with vavle at the pad

    Return side:
    six wall returns with single valve at the pad
    two swimout returns with single valve at the pad
    two step returns with single valve at the pad
    four deck jets with single valve at the pad

    So....trying to decide if two speed WFDS-4 (or -26) or single speed WFE-3 would be best.
    inground liner Grecian "L"
    34000 gallons
    1 HP whisperflo, TA100 sand filter
    Autopilot digital SWG, SC-60 cell
    Hayward Colorlogic LED lights

  9. Back To Top    #9
    mas985's Avatar
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    On the filter, bigger is definitely better but you have to choose your poison when it comes to maintenance. I have a cartridge filter which I clean maybe twice a year even if it doesn't need it so maintenance is really not an issue at all. So you have to decide if you like backwashing a sand filter more often than cleaning a cartridge filter less often.

    On the plumbing, you have quite a few parallel lines going which is good so flow rates are less of an issue unless you set the valves such that only one line is running.

    There really isn't much of a down side to a two speed pump, other than cost, and it offers the most flexibility and energy cost savings. However, if you ever plan on a solar heater on top of a two story house, be aware that it is unlikely that you will be able to use low speed with solar. It may work ok on a single story house though.
    Mark
    Hydraulics 101; Pump Ed 101; Pump and Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, 1/2 HP 2sp pump, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

  10. Back To Top    #10
    As bad as I hate to go down another bunny trail.....do you have a suggestion for a cartridge filter (size). Would prefer to stay with Pentair.
    inground liner Grecian "L"
    34000 gallons
    1 HP whisperflo, TA100 sand filter
    Autopilot digital SWG, SC-60 cell
    Hayward Colorlogic LED lights

  11. Back To Top    #11

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    duraleigh's Avatar
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    Late to chime in, as usual, but I think there's another more personal consideration about filters that's seldom mentioned...although implied.

    Part of your filter type choice should be made considering how closely you intend to monitor your pool water. If you are pretty sure you stand a good chance of "letting your pool go" from time to time and will need to do some clean-up (shock), then I believe a sand filter is the best option.

    If you are pretty sure you will keep the pool in pristine condition, then a cart or DE makes more sense to me. Cleaning up an occassionally neglected pool is somewhat easier with a sand filter.

    Now, as a new pool owner, how the heck do you know what kind of pool maintainer you'll be??

    When my pool was brand new, I kept it pristine. As it and I have both aged, I know I can let it go if I don't feel like messing with it and it's pretty easy to clean up. For that reason, I'm glad I've got a sand filter.
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  12. Back To Top    #12
    I would probably follow a similar path.....great maintenance at first but as the new wears off....well who knows. I do have an up and coming teenager but considering I can't get him to clean his room without threatening bodily harm. There is a pool in the neighborhood with a cartridge filter and they did have a very dirty pool after it sat uncovered all winter and no sod to keep the dirt down. He said he had to spray the cartridges a couple of time before he got everything under control. Can anyone who has had both types chime in on if there is a noticeable (not microsopic) difference in water quality/clarity betweem sand and cartridge? I have swam in both types and don't recall a difference.
    inground liner Grecian "L"
    34000 gallons
    1 HP whisperflo, TA100 sand filter
    Autopilot digital SWG, SC-60 cell
    Hayward Colorlogic LED lights

  13. Back To Top    #13
    mas985's Avatar
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    Dave,

    If you mean it is harder to clean up an algae bloom, then I might agree although I have never had one to clean up myself. I attribute that to my SWG.

    I am doing well if I test the water once a week so I am probably not the best at maintenance. With the SWG, I can neglect the pool for several weeks without much of an impact.


    Rockyboy,

    If you are planning on a SWG then I would say a cartridge would work fine. However, if you are going with BBB, then I would agree with Dave and probably go with sand.

    Also, you can get better filtration with Zeobrite in a sand filter instead of sand and have close to the filtration capability of a cartridge.
    Mark
    Hydraulics 101; Pump Ed 101; Pump and Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, 1/2 HP 2sp pump, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

  14. Back To Top    #14
    Budget is not unlimited soooooo.....let's say PB is tired of me whining about his equipment choice and is letting me supply my own. He will credit me $250 for either the pump or filter that he supplies. I have an extra $250 to add to that amount. Should I live with the sand and go with a two speed whisperflo or go with a one speed whisperflo and cartridge filter? Where is the money best spent? BTW, I will have an Autopilot SWG.
    inground liner Grecian "L"
    34000 gallons
    1 HP whisperflo, TA100 sand filter
    Autopilot digital SWG, SC-60 cell
    Hayward Colorlogic LED lights

  15. Back To Top    #15
    mas985's Avatar
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    I would separate the filter and pump decisions since they really are somewhat independent.

    There are many opinions when it comes to filters and it really comes down to personal preference. Given you have a SWG, you probably will not have to worry about algae blooms so either filter would work fine for you. You probably will not notice much of a difference in cleaning abilitly so it really comes down to maintenance. Backwashing a sand filter a couple of times a month vs cleaning the cartridges a couple of times a year. Probably not a big difference but that is a personal choice. There really is no best way to go only what will work best for you.

    As for the pump, you will save more money in the long run with a two speed pump and it should pay for the extra cost in less than a year or two at most. In my opinion, there is really no reason not to go with one. Low speed is more the sufficient for proper cleaning and circulation.
    Mark
    Hydraulics 101; Pump Ed 101; Pump and Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, 1/2 HP 2sp pump, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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