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Thread: calculating turn over?

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    calculating turn over?

    Question? I hear talk on here about turning over you pool at least once or more a day. Could some one give me a little help. Here is what i got. Intelliflo VS that for the math sake I am running it at 1500 rpm's. One skimmer is 96 ft away, the other is 69 feet, the main drain is 50 feet, I have 3 returns, one is 40 feet one is 50 feet, the other is 90 ft. The pump 1 1/2 feet above the pools elevation. The pipe is 1 1/2 in, thanks for any help. I really don't know where to begin.
    21x42 olympic sports pool
    18000 gal
    Intelliflo vs pump
    Pentair ic40 SWG
    Suntouch control
    TR100 Pentair sand filter
    Letro ledgen II pool cleaner
    Vinyl liner
    TF Test Kit's TF100

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    mas985's Avatar
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    Re: calculating turn over?

    Turnover is a general rule of thumb but some pools can get away with much less and some need more. To get to turnover, I have a few more questions.

    It seems as though you have three suction lines. Are they tied together at the pool with only one line going back to the pump OR do all three go from pool to pump?

    What is your filter pressure at 2500 RPM or higher?

    Is the backwash valve 1.5" as well?
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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    Mod Squad jblizzle's Avatar
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    Re: calculating turn over?

    The 1 turn over is really a suggestion and not a rule. The driving factor is really the filtration. If you pool is clear enough for you to be happy, that is good enough.

    You can shorten your pump run time some and give it a few days and then shorten it more, until the pool is not as clean as you would like ... then bump the time back up a bit and call it good.

    Someone else can try to estimate your flow rate (oh now I see Mark has posted ... he is the man), but like I said that is just a suggestion.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
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    Re: calculating turn over?

    Quote Originally Posted by mas985
    Turnover is a general rule of thumb but some pools can get away with much less and some need more. To get to turnover, I have a few more questions.

    It seems as though you have three suction lines. Are they tied together at the pool with only one line going back to the pump OR do all three go from pool to pump?

    What is your filter pressure at 2500 RPM or higher?

    Is the backwash valve 1.5" as well?
    yes 3 diff suction lines, everything on the pump and filter is 2 in.@ 2500 rpm my filter pressure is 6 psi all lines going too and comeing from the pool is 1 1/2 in.
    21x42 olympic sports pool
    18000 gal
    Intelliflo vs pump
    Pentair ic40 SWG
    Suntouch control
    TR100 Pentair sand filter
    Letro ledgen II pool cleaner
    Vinyl liner
    TF Test Kit's TF100

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    Glock30's Avatar
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    Re: calculating turn over?

    New to pools and the forum but I think I can help.
    I also have an Intelliflo pump.
    I the back of the manual there is a chart that shows gallons per min in relation to RPM of the pump.

    This is how I figured it:

    How many hours you want/need to run your pump for 1 turnover of water (starting point)
    I have 24k gallons
    I figured my pump will run about 6 hours total during the day.
    6x60 min =360 mins of run time.
    Now you need to program or "schedule" your pump to come on at a certain time at a certain RPM and run at that RPM (convert to GPM) and then calculate your GPM for that time.

    EXAMPLE:

    8:30-8:45 @750 RPM=~38GPM x 15 min. =570 GPM (pump warmup)
    8:45-9:45 @3450 RPM=~145GPM x 60 min. =8700 GPM (Super skimming)
    9:45-10:30 @1500 RPM=~65GPM x 45 min =2925 GPM

    Keep doing this with your schedule until your GPM in bold equals your total pool gallons or a bit over.
    Try to figure in when the pool is going to be used and keep the RPM lower during these times if you have kids etc.
    i.e. I am "super skimming" early in the AM to get rid of overnight surface debris and running this when no on will be swimming etc.
    Hope I helped.
    18' X 36' Inground Pool 26,000 gallons. SuperMax 27mil/27mil Vinyl Liner-Installed Fall 2011
    Pentair Intellipro Programable Pump (Model 011018) // Pentair S8M 500 Cartridge Filter // Circupool RJ45 Salt Chlorinator
    2 Hayward Skimmers // 3 Returns // 2 Savi Melody Pool lights // TF-100 Test Kit.

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    Re: calculating turn over?

    Thanks. That will help. I just wondering what kind of loss I get on pipe leather.
    21x42 olympic sports pool
    18000 gal
    Intelliflo vs pump
    Pentair ic40 SWG
    Suntouch control
    TR100 Pentair sand filter
    Letro ledgen II pool cleaner
    Vinyl liner
    TF Test Kit's TF100

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    mas985's Avatar
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    Re: calculating turn over?

    Glock30,

    I think you are over estimating the flow rate of the pump. How did you determine your plumbing curve? That needs to be determined first before you can determine flow rate of the pump. You seem to be using the run out point of the head curve which is way beyond anything the pump can do on typical plumbing.



    fishunt,

    One thing I forgot to ask is the height of the pump relative to the water level. Also, 6 PSI is pretty low so could you also give me the filter pressure at full speed (3450 RPM)?
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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    Glock30's Avatar
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    Re: calculating turn over?

    mas985.
    You are probably correct that I am overestimating as I have no idea what you just said (HAHA)
    I only used the chart in the back of the Intelliflo manual.
    Not sure how else to calculate it....
    18' X 36' Inground Pool 26,000 gallons. SuperMax 27mil/27mil Vinyl Liner-Installed Fall 2011
    Pentair Intellipro Programable Pump (Model 011018) // Pentair S8M 500 Cartridge Filter // Circupool RJ45 Salt Chlorinator
    2 Hayward Skimmers // 3 Returns // 2 Savi Melody Pool lights // TF-100 Test Kit.

  9. Back To Top    #9
    mas985's Avatar
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    Re: calculating turn over?

    If you want to give me the same information that I requested from fishunt, I can estimate the flow rate for you as well.


    I need the following:

    The suction side pipe length and diameter from pool to pump
    The number of individual suction pipes going from the pool to the equipment pad.
    The number of suction side valves
    The height of the pump relative to the water line
    The filter pressure at full speed
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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    Glock30's Avatar
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    Re: calculating turn over?

    Thanks Mark, I will try to get this tonight.
    18' X 36' Inground Pool 26,000 gallons. SuperMax 27mil/27mil Vinyl Liner-Installed Fall 2011
    Pentair Intellipro Programable Pump (Model 011018) // Pentair S8M 500 Cartridge Filter // Circupool RJ45 Salt Chlorinator
    2 Hayward Skimmers // 3 Returns // 2 Savi Melody Pool lights // TF-100 Test Kit.

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    Glock30's Avatar
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    Re: calculating turn over?

    Mark,
    Here are the numbers you requested:

    I have two Skimmers, one has 21' of pipe from pool to pump and the other has 50'.
    All pipe is 2" dia.
    Both skimmers run to valves before joining at the pump.
    I get 16 lbs pressure while running at 3110 RPM
    The pump is about 15" above the water line.

    Thanks

    Also my apologies for hijacking your thread fishunt..
    18' X 36' Inground Pool 26,000 gallons. SuperMax 27mil/27mil Vinyl Liner-Installed Fall 2011
    Pentair Intellipro Programable Pump (Model 011018) // Pentair S8M 500 Cartridge Filter // Circupool RJ45 Salt Chlorinator
    2 Hayward Skimmers // 3 Returns // 2 Savi Melody Pool lights // TF-100 Test Kit.

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    Re: calculating turn over?

    At 3450 I am at 14 psi thanks for all you help.

    21x42 olympic sports pool
    18000 gal
    Intelliflo vs pump
    Pentair ic40 SWG
    Suntouch control
    TR100 Pentair sand filter
    Letro ledgen II pool cleaner
    Vinyl liner
    TF Test Kit's TF100

  13. Back To Top    #13

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    Re: calculating turn over?

    My pump is 14 in above

    21x42 olympic sports pool
    18000 gal
    Intelliflo vs pump
    Pentair ic40 SWG
    Suntouch control
    TR100 Pentair sand filter
    Letro ledgen II pool cleaner
    Vinyl liner
    TF Test Kit's TF100

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    mas985's Avatar
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    Re: calculating turn over?

    Both of you seem to have very low head loss setups. I am estimating:

    fishunt - Flow rate (GPM) = RPM / 32

    Glock30 - Flow Rate (GPM) = RPM / 27
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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    Glock30's Avatar
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    Re: calculating turn over?

    Ummmmm. Is low head loss good?
    So you mean if I take my RPM and divide it by 27 I get my GPM?
    Sorry but I need to make sure of this. (I understand it is an estimate.)
    THANKS
    18' X 36' Inground Pool 26,000 gallons. SuperMax 27mil/27mil Vinyl Liner-Installed Fall 2011
    Pentair Intellipro Programable Pump (Model 011018) // Pentair S8M 500 Cartridge Filter // Circupool RJ45 Salt Chlorinator
    2 Hayward Skimmers // 3 Returns // 2 Savi Melody Pool lights // TF-100 Test Kit.

  16. Back To Top    #16
    mas985's Avatar
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    Re: calculating turn over?

    Low head loss is usually good but in rare occasions can cause problems if it is too low.

    Yes, divide your RPM by 27 and that will give you your flow rate.

    Estimates are probably within 5%.
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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    Re: calculating turn over?

    It's easy to install a flow meter. You just need a straight section of about 1-2ft on either side for better readings. I couldn't get that but I installed one anyway, at least I have a minimum flow rate.

    They can be had for about @$50. Just be sure to get one that matches the diameter of your PVC.

    Search Google Shopping for "blue-white flow meter"
    18K Gals, Intelliflo VSD, Pentair Catridge, SWG, Solar & Gas Heat, Pebble Tec, Jandy AquaLinks, Pool Pal for Android.

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    Mod Squad jblizzle's Avatar
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    Re: calculating turn over?

    Note that the accuracy of those flow meters are +/-10% of the max flow ... so a 100gpm max gauge is accurate to within +/-10gpm.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

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