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Thread: Hydraulic Problem? Unbalanced equipment power?

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    Hydraulic Problem? Unbalanced equipment power?

    I don't recall ever having such a hard time opening the pump basket top or the filter top to clean the element. I have to use a rubber mallet for both or there's no way.

    I'm concerned that this may be a symptom of something else wrong due to the high PSI the cartridge filter is registering. Granted, I don't know how high the PSI was before, since we didn't use the pool much since we moved in, in 2000. Actually, we didn't use it. It's been green.

    Three weeks ago I started cleaning up the pool. I started by replacing the PSI meter since the old one was not registering and would be hard to read anyway bcz of a very cloudy, crackled yellowed face. I also replaced the filter element with a Home Depot one.

    After removing the mountain of dead algea, I treated with PoolTime's Algicide 50% and have been vacuuming to waste every other day, constantly cleaning the filter every hour and maintaining a 5 ppm chlorine, it's been 3 weeks, yet no clear water. Now I wonder if I should upgrade and purchase the 120 sq ft Hayward or the 150 sqft Pentair or should I go with a 90 sq ft or less filter?. Which brings me to be concerned with the correct hydraulics for this system. I want to make sure the right pump and size filter is put in since some old solar heater and a gas heater are no longer attached and in use.

    I have an in-ground 27x 13, concrete 10,500 gal pool, 6 @ deepest end. It has a whilrpool section as well with a blower and 3 inlets. Considering the high water table on our barrier island, the concrete pool deck is elevated approx 3 feet. The pipes run underground along the side of the pool deck, which makes it 3 feet below the water line, although the pump sits on a slight elevation of cinderblocks, bringling it almost level with the pool line, but not quite. 2" pipes are hooked on to a 1+1/2 HP (3450RPM) GE pump, and onto a Hayward C-1100 (100 sqft effective filtration and 100 sqft design flow rate, Max PSI 50).

    Is the pump too strong and could it be causing a more intense water velocity than is necessary? When we moved in in 2000, the pool was hooked up to pipes leading to a Solar Heater on the roof of the house about an extra 20 feet away. It wasn't long after a hurricane took it and our roof, so we removed the Solar Heater and hooked the pool up to an existing gas water heater, less than 10 feet away from the pool just past the pump and filter. The heaters might have required a 1+1/2 pump whereas now?.

    When I put the new cartridge in, it initially registered at 20 PSI. I keep it as clean as the first day of purchase. With the only difference being it's wet, an hour after its first use, the filter started registering 30 at startup. Now it's registering at 35 at startup. As well, the filter HAS HAD a hairline crack at the point where the pipe from the pump comes into it. The hairline is now causing a 6" loss in pool water on a 6 hour day of filtering.

    Does it sound like a I have a bigger problem than just needing a new filter?

    What size filter should I go for, the bigger one or the smaller one - or -
    in the interest of my pipes, should I get a pump with less punch? Like a 1 HP?

    Does anyone know a link to a chart of RMP = GPM?

    Turbomango
    Mother of two Maltese Champs
    IG 27x 13; Concrete - marcite rectangle, era mid 1980s; 10,500 GAL. - 6' @ deepest end. Whirlpool section w/ floor blower, floor drain & 3 inlets. 3' elevated concrete deck. Pipes run underground along the side of the pool deck, which gives it 3' below the water line location; pump sits on elevation of cinderblocks, bringling it almost level with the pool line, but not quite. 2" pipes connect to 1+1/2 HP (3450RPM) GE pump, and Hayward C-1100 (100 sqft effective filtration and 100 sqft design flow rate, Max PSI 50). Location: Barrier Island, high water table. Objectives: Short term- Replace filter. Mid - Resurface pool, Resurface Deck with KoolCrete or like, Long Term - Landscape for privacy.

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    JasonLion's Avatar
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    Welcome to TFP!

    I reccomend getting a larger filter. The one you have should be able to handle that pump and the pressures you mention but a larger filter will do so more gracefully, need to be cleaned less often, and generally be easier to deal with.

    The pressures you describe are not normal. Either the cartridge is not getting cleaned well enough, or it needs to be replaced, or there is some blockage in the pipes. You might try cleaning the cartridge normally, then soaking the cartridge in water with powdered automatic dishwasher detergent overnight and then rinsing it off.

    You may well need the 1 1/2 HP pump to drive the whirlpool effectively, however it wastes electricity for regular filtering. This is an ideal situation for a two speed, or variable speed, pump. You could run the pump on high when using the whirlpool and on low the rest of the time and save quite a bit on electricity. On the other hand if the pump is working just fine and you aren't in an area with extreme electrical rates it might be best to leave it alone till it gets older.
    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

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    Hydraulic Problem? Unbalanced equipment power?

    [align=center]
    I recommend getting a larger filter. The one you have should be able to handle that pump and the pressures you mention but a larger filter will do so more gracefully, need to be cleaned less often, and generally be easier to deal with.

    The pressures you describe are not normal. Either the cartridge is not getting cleaned well enough, or it needs to be replaced, or there is some blockage in the pipes. You might try cleaning the cartridge normally, then soaking the cartridge in water with powdered automatic dishwasher detergent overnight and then rinsing it off.

    You may well need the 1 1/2 HP pump to drive the whirlpool effectively, however it wastes electricity for regular filtering. This is an ideal situation for a two speed, or variable speed, pump. You could run the pump on high when using the whirlpool and on low the rest of the time and save quite a bit on electricity. On the other hand if the pump is working just fine and you aren't in an area with extreme electrical rates it might be best to leave it alone till it gets older.
    [/align]



    Wow, JasonLion, Sir, thank YOU for such a swift and accurate reply. And thanks for the welcome!

    I was looking to purchase Hayward's Star Clear Plus C12002 (120 sqft/120GPM) or Pentair's 150, but when I read the C12002 specs on Hayward web site, they call for a pump that pumps 120 to 130 GPM for that model filter. I have no idea how to figure GPM for my 1+1/2 HP pump, ANyone know of a chart or some online program software?

    Hayward also has a .pdf file on pump/filter sizing... which talks hydraulics and gives a generic formula so pool owners can figure out Min/Max Turnover Rates. I didn't expect to get involved in the technical stuff, like hydraulics, but being the pool is from the 80s, all this info made me want to confirm the accuracy of the installed equipment and also if my potential purchase for a Pentair 150 or Hayward 120 will be wise. Actually, I've surprised myself that I understood some of this while I was reading it, but honestly, its too technical.

    So, figuring the math, my Min Turnover Rate is 22GPM/8hrs and the Max seems to be 63GPM at 6 feet, 84GPM at 8 feet. I don't know what all this really means in terms of pump and filter strengths. From what I read on velocity, I am worried about my old PVC pipes which will be a bummer on our wallet if I installed wrong equipment that will cause us problems. That's why I'm wondering if the Pentair 150 would be best.

    The cartridge is brand new. Last week's purchase from Home Depot (last Wednesday). I'm cleaning the cartridge with a garden hose and a strong single stream of water from a good wand. It penetrates well into the folds. Comes out white and seems clean as can be between the folds when I'm through with it, but I will do the overnight soak as you prescribed. Seems like I have to clean it this often bcz I read one should when the PSI rises 10 points -- as this one does from the initial 30 or 35. At 40 or 45 -- goodness, I never let it go to 45 anyway, I wash it. The water is not so dirty now, I can see the first 2 of three steps, and I have no more frog caviar to greet me in the mornings, but a small amount of cloudy material is washed out from the filter when I do clean it.

    I failed to mention that the pump loses prime every once and a while, and water drops down low in the pump basket area. My pool man thinks its the low quality material this non-Hayward cartridge is made of that's causing the problem. I don't know. Could the prime-loss also be caused by the leak in the filter?

    Thanks for your time!
    IG 27x 13; Concrete - marcite rectangle, era mid 1980s; 10,500 GAL. - 6' @ deepest end. Whirlpool section w/ floor blower, floor drain & 3 inlets. 3' elevated concrete deck. Pipes run underground along the side of the pool deck, which gives it 3' below the water line location; pump sits on elevation of cinderblocks, bringling it almost level with the pool line, but not quite. 2" pipes connect to 1+1/2 HP (3450RPM) GE pump, and Hayward C-1100 (100 sqft effective filtration and 100 sqft design flow rate, Max PSI 50). Location: Barrier Island, high water table. Objectives: Short term- Replace filter. Mid - Resurface pool, Resurface Deck with KoolCrete or like, Long Term - Landscape for privacy.

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    Found the Culprit for Prime Loss: Pump Leak

    Found the Culprit for Prime Loss: Pump Leak

    The pool man took it apart the other day to clean out the impeller and we thought he tightened it well after the second time, but I guess not!
    IG 27x 13; Concrete - marcite rectangle, era mid 1980s; 10,500 GAL. - 6' @ deepest end. Whirlpool section w/ floor blower, floor drain & 3 inlets. 3' elevated concrete deck. Pipes run underground along the side of the pool deck, which gives it 3' below the water line location; pump sits on elevation of cinderblocks, bringling it almost level with the pool line, but not quite. 2" pipes connect to 1+1/2 HP (3450RPM) GE pump, and Hayward C-1100 (100 sqft effective filtration and 100 sqft design flow rate, Max PSI 50). Location: Barrier Island, high water table. Objectives: Short term- Replace filter. Mid - Resurface pool, Resurface Deck with KoolCrete or like, Long Term - Landscape for privacy.

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    duraleigh's Avatar
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    Turbo,

    Welcome to the forum. In your discussions about the filter, I am reading into that that you think your water will not clear because of the filter. That is not the case.

    YOu need to clear your pool with chlorine.....lots of it. 5ppm is not adequate to clean up a swampy pool. If you don't have a good test kit, take a sample of your water to the pool store and get them to test for Free Chlorine, pH, Alkalinity,
    Calcium and CYA. Post those results up and you'll get lots of great help on clearing your pool. Read the "Stickies" section and start asking lots of questions.

    I may have misinterpreted your post but do not change the filter out hoping that will clean up your pool...it won't. Getting an understanding of what you need to do to your pool water will clear it up and then your filter, new or old, will keep it that way.

    PS - you may still need the filter if your having mechanical issues with your old one but it's not causing your cloudy water.
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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