Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 6 of 6

Thread: Pentair Rainbow 300 Chlorinator Issue

  1. Back To Top    #1

    Pentair Rainbow 300 Chlorinator Issue

    Not sure which forum this should go in, so I am going to fire away here. I just replaced my old 300 with a new 300 chlorinator. My understanding is that when the pump turns off, the water is supposed to drain our of the chlorinator. Is this correct? I've noticed on mine that water is remaining in the unit. Once I open the top, the water then drains out. Anyone have any guess as to why it is not draining correctly? My first guess would be one of the valves is old. clogged, etc., but everything is brand new. Thanks for any feedback/advice in advance.

  2. Back To Top    #2

    Join Date
    Jan 2013
    Houston, TX

    Re: Pentair Rainbow 300 Chlorinator Issue

    When you open the lid you release the vacuum on the system allowing the water to drain. Under normal operation the water is pushed through the cylinder. It is functioning as it should, no worries.
    TFP Moderator Chris V. ~16K Pool & Spa, 48NSF DE, IG Plaster Circa 2000, Intermatic PE653, Challenger pump with a 2 speed B2984, 20gal stenner chlorine injection, Houston, TX
    One cannot follow Islam and Christianity at the same time, nor can one follow pool store methods and TFP at the same time.
    Pool School -- Pool Math -- TF-Test Kit

  3. Back To Top    #3

    Re: Pentair Rainbow 300 Chlorinator Issue

    Ok, thanks. So I guess it doesn't drain when the pump turns off? Seems like the tabs will just dissolve faster if they continue to sit in water while the pump is off.

  4. Back To Top    #4
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Tucson, AZ

    Re: Pentair Rainbow 300 Chlorinator Issue

    Are you aware of the CYA/FC relationship and the fact that the exclusive use of tablets may accumulate CYA in the pool, allowing algae to grow if the FC is not also correspondingly raised?

    Very few members here use these chlorinators for the reason described above.

    ESPECIALLY in TX where you may not be able to drain and replace water when the CYA gets too high.

    Please add your pool details to your signature and location to your profile as described HERE as it will help us help you.
    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!

  5. Back To Top    #5
    Diver's Avatar
    Join Date
    May 2011
    South of Boston

    Re: Pentair Rainbow 300 Chlorinator Issue

    Quote Originally Posted by funkeruski View Post
    Ok, thanks. So I guess it doesn't drain when the pump turns off? Seems like the tabs will just dissolve faster if they continue to sit in water while the pump is off.
    i had the same issue with my 320 model. there was a little bit of water with the chlorinator valve in off position. and also when it was turned on, when the pump shuts off it would hold some water as well. the tabs don't dissolve that fast, especially if the water is not flowing. i don't think it's a big issue.
    26K In-ground Vinyl Pool | Hayward DE4820/SP0710XR50 filter | 1.125 HP Dual Speed Hayward Super Pump | Aquasol Solar

  6. Back To Top    #6

    Join Date
    Jul 2012
    Whidbey Island, WA

    Re: Pentair Rainbow 300 Chlorinator Issue

    am using Rainbow while raising CYA

    same problem here, water does not drain

    directions say

    1. Turn control valve to the closed position. SHUT OFF PUMP.
    2. Wait one minute. This will allow water and fumes to drain from feeder.
    3. Leave control valve closed and turn on pump. The check valve will prevent water from
    entering the feeder.

    but #2 seems to not be true

    which is a problem cuz when you add tabs the water can splash or overflow and is nasty
    so why is #2 not true now in 3 cases

    searched but did not find "the answer"

    thank you

    PS I put a query on the Pentair forum
    Last edited by engrav; 07-19-2014 at 09:48 AM. Reason: add a sentence
    IG under fir trees and one cherry surrounded by grass built in 1979, 30k, plaster, old Sta-Rite HRPB30, 4.9 sq.ft, 20 GPM/sq.ft., but with new glass, new (in 2012) 1 HP WhisperFlo one speed, new (in 2013) Rainbow tab chlorinator attached at the top, old Maxi-Flo Heat Exchanger MF-260, Burnham V7 oil heater 245 MBH, new (in 2012) Compool to Easytouch, Taylor K-2005 and TF-100.

Posting Permissions

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