Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 10 of 10

Thread: Plumb Return Lines to BOTTOM of Pool?

  1. Back To Top    #1

    Plumb Return Lines to BOTTOM of Pool?

    The other big advantage touted by in-floor cleaning system manufacturers is that they put the return water where you really want it, at the bottom of the pool. That seems desirable since it would would put the warm water low breaking up thermoclines but are there any downsides?

    I asked my PB why returns aren't floor mounted in pools without in-floor cleaning and surprise he said that its an option and whipped out a floor mounted return he had right there in the truck.

    Yet nobody does it. There must be a good reason or is it just tradition maybe from before most pools had heater?
    33'x15' x 52" Aqualeader
    Gallons ? - (I use appx 13,500 to calculate "stuff")
    33 x 15 x 4.3 x 5.9 = 12,558. or . . The Pool Calculator = 14,400
    Hayward S-166T 100Lb Sand Filter - Hayward Power-Flo LX 1HP Pump
    Intex S.W.G.

  2. Back To Top    #2
    stever's Avatar
    Join Date
    Nov 2007
    Location
    Escondido, CA (near San Diego)
    Posts
    285

    Re: Plumb Return Lines to BOTTOM of Pool?

    I think there's good reason for returns to the bottom -- I notice a very cold zone sitting at the bottom 3 feet in the deep end. After a few minutes of swimming with the kids, it's gone, but I believe that it would heat better if the hottest water were not all at the top.

    The onnly drawback I can think of is that without high aimed returns, the water would not be pushed in a circle to clean off the top into the skimmer.

    If I want to mix it up, I'll turn on the cleaner to suck water from the bottom (and return to the top). Or I'll put the skimmer float in really fast and cause it to suck to the bottom, causing the skimmer to turn off and the bottom drains to function (almost no suction to the bottom with skimmer on). This will re-open the skimmer if I forget the next time the pump turns off (the float will float).

    Steve
    Pool: 625 SF Free-Form In-Ground Shotcrete Pool w/7.5' dia spa.(8 jets), 24" raised bond beam (22,500 gal)
    Pentair Equip: Intelliflo VF Pump, MasterTemp 400 Heater, IC40 SWG, Quad DE 100 Filter
    Automation: IntelliTouch i7+3 (+ extender panel), 6 Jandy Automated Valves (S, R, Spa Bypass, Solar, Cleaner, Spillway)
    Other: 75% Solar, Kreepy Kruiser Cleaner, Tan Hip-Hop Diving Board (a bit curved) on 606 Cantilever Base (SR Smith)
    Links: [TFP Pool Build Thread] - [TFP Landscaping Thread]

  3. Back To Top    #3
    launboy's Avatar
    Join Date
    Jun 2008
    Location
    S.E. Wisconsin
    Posts
    582

    Re: Plumb Return Lines to BOTTOM of Pool?

    It makes sense to me. I've never seen a residential pool with this feature before, but many public pools have them. A local one has a combination of wall and floor returns. The new Sixflags waterpark also uses in-floor returns in the wave pool.

    If you want to have the equivalent of an in-floor return, you could unscrew the eye-ball and screw in a threaded adapter with enough PVC to reach the bottom with an elbow on the lower end. This would have the added benefit of being directional if you turn the elbow.

    This could also be accomplished by putting the return eyes(new construction) just above the floor in the wall.

    HTH,
    Adam
    18' x 42" Intex Easyset Pool, with 16' x 52" deep end in the middle. Approx. 5500 Gal.
    Hayward Power-Flo LX 1 HP, 100# Jacuzzi Brand Sand Filter(Piped underground so it looks nice) 8)
    3 - 2' x 20' Solar Pool Heater Panels(roof mounted)
    Goin' on 9 summers...NOBODY thought it would last this long.
    Buried Portable Spa sharing pumps and water with pool (Almost complete project)

  4. Back To Top    #4

    Join Date
    Oct 2007
    Location
    Central Texas
    Posts
    104

    Re: Plumb Return Lines to BOTTOM of Pool?

    Since I built my own pool and did my own plumbing I decided to put in floor returns. So I do have 13 floor returns but I just got water in the pool two days ago, so I can't say if they are effective.

    I am plumbing the pad so that I can direct all flow to either the walls or the floor. I can also open them all at once. I did this so I can send heated water to the bottom (future solar project) and so I can get better water mixing and perhaps a more even distribution of chemicals. If I install the solar, I will automate this changeover with a control system.

    However, residential pools have been getting along just fine without floor returns so they are probably not a requirement. I put them them in because I thought I could use them in my application and they were relatively inexpensive since I did the work myself.
    Light grey plaster, stone coping, 38K gallon Roman shaped pool with a shallow end beach, table and bar stools, deep end bench and waterfall (Intelliflo 4X160). Taylor K-2006, Pentair 320 chlorinator, Intelliflow VF, Quad DE 100. 4 ColorLogics, 3 skimmers, 14 wall returns, 13 floor returns, TurboTwister slide, autofill and miles of pvc.

  5. Back To Top    #5
    Guest

    Re: Plumb Return Lines to BOTTOM of Pool?

    Reverse flow pools are not a new idea. They have been tried many times. The reason it's not more commonly done is because there is no real advantage in actual use and often the costs are higher. In the fancier systems the pools have special valves than run normally when the pool is not heated and reverse the flow when the pool is heated but in actual practive there is not a true advantage in the majority of installations.

  6. Back To Top    #6

    Join Date
    Jun 2007
    Location
    New Jersey
    Posts
    651

    Re: Plumb Return Lines to BOTTOM of Pool?

    When I had AnthonySylvan build my pool in 2004, it came with a line to the main drain from the filter return manifold. They promoted it as a way to warm the pool for free. I think it works--at least it DOES reduce the hot surface, freezing bottom syndrome I had in my previous pool. I don't know if they still do that, but the cost at build is minimal--a few feet of 2" PVC line, two 2-way instead of single Jandy valves plus a tee and an elbow or two.
    Current: 28,000G 18'x36' I/G AnthonySylvan Plaster; Waterway 60 sq.ft. DE Filter; 1.0hp x 1.65 SF Two-Speed (B2982) WhisperFlo; 2004-Present
    Previous: 40,000G 20'x40' I/G Koven unlined WWII salvage 5/8" marine steel; Lomart Stainless Sand Filter; 3/4hp Hayward SuperPump; 1946-2003 (managed by me from about 1964)
    Ancient Taylor K-2000, upgraded with Taylor CH, TA, and FAS-DPD, and TFT CYA tests.

  7. Back To Top    #7
    spishex's Avatar
    Join Date
    Oct 2008
    Location
    Hillsborough, NC
    Posts
    1,375

    Re: Plumb Return Lines to BOTTOM of Pool?

    I've seen two styles of in-floor returns. Some are the zoned pop-up style and the others are just standard returns with vents covering them on the floor. Usually in the non pop-up pools, there are far less returns (4-6).

    The problem with the standard style is they send the water straight up and don't do much for mixing or surface movement. That can lead to a lot of dead spots and requires a lot of brushing.

    The pop-up ones do a great job of getting a lot of surface motion, but they break. That's not to say the standard ones don't, but when you've got a dozen or more little moving parts in your pool you've got a lot of... potential.

    So long story short as waterbear alluded to: money. More expensive to build, much much much more expensive to fix, and in many cases not even as effective as two or three standard eyeballs.

  8. Back To Top    #8

    In the Industry
    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    28,396

    Re: Plumb Return Lines to BOTTOM of Pool?

    First, I agree with Evan and Tim that, for the most part, pop-ups are problematic. From a DIYer standpoint, that's a deal-breaker. If you are willing to pay to keep them operational, they may be quite convenient.

    Second, the pupose of my post is to hijack the thread a little. There's a couple of references above about colder water in the deeper part of the pool. I'm curious how many of you experience this. My assumption is that an adequate number of returns, aimed properly, should prevent any temp variation.

    My pool is only 6 feet deep so I may be misjudging how many deeper pools are experiencing this issue.
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  9. Back To Top    #9
    stever's Avatar
    Join Date
    Nov 2007
    Location
    Escondido, CA (near San Diego)
    Posts
    285

    Re: Plumb Return Lines to BOTTOM of Pool?

    Our pool's deep end is really cold now -- but so is the rest of it...

    But seriously, in the summer when the pool was 86 or 87, when we first got in, the bottom 30 inches or so was noticably colder. I tried to stay at the bottom with our thermometer (floading kind), but could not stay down there long enough for it to record a difference. Might have been 2 degrees cooler.

    Once we swam around a little it mixed up. I do not have pointable returns, just pvc pipes to the face of plaster cut off. We were told nobody puts pointable returns on anymore (yeah, right). They are angled in the wall to get circulation, but have no adjustment.

    Of course having the cleaner run will circulate water from the bottom to the top. I have my cleaner run in the middle of the night so it won't interfere with the solar (solar would increase pump GPM and cause the cleaner to become 'over-excited'). My day, the water has settled into two definite zones.

    Steve
    Pool: 625 SF Free-Form In-Ground Shotcrete Pool w/7.5' dia spa.(8 jets), 24" raised bond beam (22,500 gal)
    Pentair Equip: Intelliflo VF Pump, MasterTemp 400 Heater, IC40 SWG, Quad DE 100 Filter
    Automation: IntelliTouch i7+3 (+ extender panel), 6 Jandy Automated Valves (S, R, Spa Bypass, Solar, Cleaner, Spillway)
    Other: 75% Solar, Kreepy Kruiser Cleaner, Tan Hip-Hop Diving Board (a bit curved) on 606 Cantilever Base (SR Smith)
    Links: [TFP Pool Build Thread] - [TFP Landscaping Thread]

  10. Back To Top    #10
    mas985's Avatar
    Join Date
    May 2007
    Location
    Pleasanton, CA
    Posts
    9,908

    Re: Plumb Return Lines to BOTTOM of Pool?

    I have an 8 1/2' deep end with solar but I haven't really noticed cold spots in the deep end. Then again, I also have 4 returns and the one in the deep end I have pointed downward so I think that accomplishes the same thing as having one at a lower position. Also, removing cold water from the deep end with a main drain should have the same effect as having a lower return.
    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, ThePoolCleaner

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •