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

Thread: How many take a shower before getting in the pool?

  1. Back To Top    #1
    ned8377's Avatar
    Join Date
    Apr 2015
    Location
    Wake Forest, NC
    Posts
    239

    How many take a shower before getting in the pool?

    I've seen reports of this parasite over the years but it was on ABC News again last night so I did some research and found this very interesting thread where chem geek gives a pretty good explanation of the situation you would be faced with if you had some of the CYA levels recommended on this forum.

    Response to Cryptosporidium Post

    I've looked around on the web and can't find a test. I think it is hard even for a doctor to find a lab that can test fecal matter in a patient for it. I know this mainly pertains to public pools and I'm not trying to be an alarmist but since the post cited above was in 2008, I was wondering if anyone had anything to add. It seems to me if you had CYA levels of 30 or 60 to 80 ppm you would basically be up the creek. Is that right? Of course you could spend $$$ on ozone and ultraviolet lights or drain your pool. This is all worst case scenario of course. I guess it eventually dies after about 10 days under normal or higher than normal chlorine conditions but I don't know. One thing I do know is that no one at my house takes a shower before getting in the pool.
    True L 45,000 gal Hayward IG vinyl pool. Hayward Tristar 2.40 THP; 1.5 FRHP/1.60 SF. Hayward Model # S310T2 Sand Filter. Aqua Rite T-15. Aqua Comfort 154,000 BTU Heat Pump. TF-100

  2. Back To Top    #2
    Mod Squad tim5055's Avatar
    Join Date
    May 2014
    Location
    Columbia, SC
    Posts
    8,495

    Re: How many take a shower before getting in the pool?

    I generally do not. The best thing for me is to jump in the pool after getting done mowing the lawn.
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

  3. Back To Top    #3
    ned8377's Avatar
    Join Date
    Apr 2015
    Location
    Wake Forest, NC
    Posts
    239

    Re: How many take a shower before getting in the pool?

    I know what you mean. Nothing like being hot and sweaty from work or working out and then jump in the pool.
    True L 45,000 gal Hayward IG vinyl pool. Hayward Tristar 2.40 THP; 1.5 FRHP/1.60 SF. Hayward Model # S310T2 Sand Filter. Aqua Rite T-15. Aqua Comfort 154,000 BTU Heat Pump. TF-100

  4. Back To Top    #4
    ned8377's Avatar
    Join Date
    Apr 2015
    Location
    Wake Forest, NC
    Posts
    239

    Re: How many take a shower before getting in the pool?

    This was meant to be a serious post. Any comments about Cryptosporidium?
    True L 45,000 gal Hayward IG vinyl pool. Hayward Tristar 2.40 THP; 1.5 FRHP/1.60 SF. Hayward Model # S310T2 Sand Filter. Aqua Rite T-15. Aqua Comfort 154,000 BTU Heat Pump. TF-100

  5. Back To Top    #5
    Mod Squad pooldv's Avatar
    Join Date
    Aug 2012
    Location
    DFW, TX
    Posts
    23,998

    Re: How many take a shower before getting in the pool?

    No shower before swimming ever.

    Chem geek is the resident expert on all things chemistry and sanitation.
    TFP Moderator
    If TFP helped you or saved you money - Become a TFP Supporter! <--Click here
    2012 build and pics, 20k gal gunite, black onyx pebblesheen, OK flagstone, IntellifoVS, cart filter w/Pleatco, IC40 SWG, Solartouch, 5 12'x4' solar panels, HP50HA heat pump, 8mil solar cover, borates, TF-100 test kit, SONOS, Doheny's Discovery Robot, hot tub on bleach

  6. Back To Top    #6

    Join Date
    Mar 2007
    Location
    San Rafael, CA USA
    Posts
    12,082

    Re: How many take a shower before getting in the pool?

    Taking a shower has nothing to do with preventing Crypto in a pool. The reason to rinse off before going into a pool is to reduce the bather waste. That's something more important for commercial/public pools due to their high bather-load. It's also something one can consider before using their spa if they want their water to last longer between water changes.

    In a pool with CYA, then it is difficult to get rid of Cyrpto using chlorine. You'd have to raise the FC to be at least 10 ppm higher than the CYA level to be roughly equivalent to 10 ppm FC with no CYA and in practice to be sure given errors in testing you'd raise the FC to be 20 ppm higher than the CYA level and you'd maintain it that way for 24 hours. While not impossible, this isn't very practical.

    It does NOT die out after 10 days in a pool with CYA. They are talking about a pool with no CYA. For a pool at the minimum FC/CYA ratio of 7.5%, this is equivalent to a pool with 0.06 ppm FC and no CYA so with the 15,300 CT value that implies a 99.9% reduction after 177 days (about 6 months). The 10 days they are talking about would require exposure to around 1 ppm FC with no CYA. Remember that our pools have an active chlorine level that is around 17 times lower than this 1 ppm FC with no CYA found in some commercial/public pools and is why the effects on swimsuits, skin, and hair and the rate of disinfection by-products is so much less in our pools than in some commercial/public pools.

    It is much easier to just do an emergency remediation dose of sodium chlorite to produce chlorine dioxide from the chlorine in the water and finally the CDC in the Model Aquatic Health Code (MAHC) now talks about that and because it is just for emergencies it's something the EPA won't balk at or at least will let the States do what they want.

    Crypto does not get blown in from the air -- it's not like algae spores -- and it is not ubiquitous in soil -- it's not like bacteria. It comes from people and animals though the Cryptosporidium parvum that infects people almost all comes from other people (i.e. transmission from animals is far less common as the specific protozoan species is different such as Isospora with cats and dogs and with Eimeria with cattle though cattle also harbor Parvum so are the primary infectious source from animals after person-to-person transmission). It is found in the majority of surface water though normally at low levels too low to cause infection (but not always which is why when camping one wants to use either chlorine dioxide or a microfilter). Crypto specifically gets transmitted through fecal matter discharge usually from diarrhea. This is why this is usually a non-issue for residential pools since you don't normally invite sick people (including kids) with diarrhea to use your pool. It happens in commercial/public pools because some people are irresponsible and go to swim in spite of being sick. The problem with commercial/public pools is that a single sick individual can then infect dozens to hundreds of others and the pathogen can exist for weeks in the pool and patrons carry it from one pool to another if they visit more than one facility.

    We have never had a single report of a residential pool having Crypto and I haven't seen any reported in any CDC Surveillance studies in spite of the CDC getting reports from health professionals, not just from commercial/public pools. I'm sure that there may be some instances, but they are very rare. Even the incidence rate in commercial/public pools on a percentage of pools per year basis is quite low. Specifically, out of approximately 300,000 commercial/public swimming pools in the U.S. (vs. around 10 million residential pools roughly evenly split between in-ground and above-ground), the total from 1999-2008 of 122 Crypto outbreaks in treated pools is 0.04% and that's over 10 years (so it's a rate of 0.004% per year). Even the 90 outbreaks reported in 2011-2012 would be a rate of 0.015% per year). Now in terms of numbers of bathers the percentage is higher because one outbreak can affect many bathers, but the point is that not very many pools are affected in spite of the panicked news report (and the CDC is intentionally doing press releases on this because they want the public not to swim when they have diarrhea). It is the main pathogenic issue in chlorinated pools because it is so chlorine resistant, but again I wouldn't worry about it for one's own residential pool. Just avoid inviting anyone over to use the pool that has a gastrointestinal illness particularly with diarrhea. Also note that even most people with diarrhea do not have Crypto.

    Now if you really are still concerned in spite of the facts that it's essentially a non-issue for residential pools, then there are several ways of handling it:

    • Use an ozone or UV system in the water circulation path. This will NOT prevent immediate transmission of the disease but it will clear the water to the 99.9% reduction after 7 turnovers (so with 6 hour turnovers that's about 2 days running constantly)
    • Use a coagulant with fine filtration such as Seaklear PRS Stage 1 and 2
    • Superchlorinate for remediation with an FC that is at least 10 and preferably 20 ppm higher than the CYA level for 24 hours (note that this is very harsh so could bleach medium blue vinyl liners)
    • Use 2 ppm chlorine dioxide overnight (12 hours) by adding sodium chlorite to a pool with chlorine and CYA in the right amounts
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

Posting Permissions

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