Bleach in a church pool??

[Sumo1]

Note to moderators: If you think this thread should be listed under pool operations, please move it-thanks.

I've just been asked to take over operation of our church pool and have accepted the challenge. I say "challenge" because, at 175,000 gallons, the pool is about 6 times the size of mine. My question is: Would it make sense to try to operate a pool this size using liquid bleach instead of using granular and pucks, as has always been done before? I welcome comments and opinions from POOLSEAN, WATERBEAR, CHEM GEEK, WASTE, and anyone else whose monikers I don't know. Thanks in advance! Hal

[chem geek]

The answer partly depends on the chlorine usage in the pool. If you know the typical chlorine usage (you can give it as number of pucks per week, etc., if you know the weight or size of the pucks) then you can see how much bleach you would need to add (I give generic numbers below for 1 ppm FC). If you do not know chlorine usage, then you can answer the following questions to help estimate it. Is the pool open to direct sunlight? Is it ever covered and if so when and with what kind of cover (opaque or clear for solar)? What is the typical bather load -- how many bather-hours per day? What is the typical use of the pool -- is it light wading or heavy competitive swimming (I suspect mostly splashing and wading with some swimmers). What temperature is the pool kept at?

To add just 1 ppm FC to this size of pool requires 1.4 gallons of 12.5% chlorinating liquid or 2.8 gallons of 6% bleach or 2.3 pounds (about 4.2 cups) of 65% Cal-Hypo or 1.6 pounds (3.2 3" 8-ounce tablets) of Trichlor.

This size of pool could use an automated chlorination system, whether it be SWG or chlorinating liquid injector or Trichlor puck feeder. Of course with Trichlor, you have to be careful about CYA rising too much. What kind of filter does the pool have and if it's D.E. or sand, what volume of water is backwashed how frequently? You might be able to use Trichlor exclusively if you dilute the water frequently enough to keep the CYA in check and you could keep the TA high to have the outgassing of carbon dioxide balance the acidity of the Trichlor (so you would just be adding Sodium Carbonate / Soda Ash / Washing Soda and sometimes Sodium Bicarbonate / Baking Soda every now and then to maintain the TA and pH. Of course that wastes a lot of water, but if you already have a D.E. filter that might be the best option. If CYA levels rise too quickly, then alternating with granular Cal-Hypo can be done for a while, but then calcium will eventually rise. Without sufficient dilution (either regularly or in an annual drain/fill adjustment), neither Trichlor nor Cal-Hypo can be used as the only chlorine sources.

Richard

[CarlD]

The rules are the same. You just use amounts for 175,000 gallons. You will probably find that using 12.5% liquid chlorine will make the job easier. It's the same as bleach, just stronger.

I need to re-check my figures but I believe 1 5-gallon carboy of 12.5% Liquid Bleach will add 3.57 ppm to your Free Chlorine level. Of course, 1 gallon will add 1/5 of that.

Using powders and pucks will give you the same problems with lowering pH and raising CYA too high that they do in smaller pools.

You WILL need to check your levels every day, probably twice a day and adjust as needed.

I'm no whiz with bather load, but that too has an effect. Be sure that babies in diapers are NOT allowed in the water. And watch for little kids urinating in it--hard to avoid.

I would tend to say run the FC closer to the high end of recommendations because of the bather load, to keep the pool sanitary.

Hope this helps.

[waste]

Sumo, I salute your willingness to help out the church by taking over the pool! Please know that you'll always find people here to help you with any questions you may have.

If by using bleach, you mean use liquid chlorine - many,many commercial/ public pools use liquid chlorine as their primary sanitizer. On www.poolsolutions.com Ben speaks of it in Tip # 72. When I worked in Va. our company provided Lifeguard and caretaking service to 40+ commercial pools and all used sodium hypochlorite (liquid chlorine) with a peristalic feed pump. The pumps can be a real pain to get the feed 'just right', this thread has discussion on them http://www.poolforum.com/pf2/showthread.php?t=1549, which might be worth a read. The trouble, as I think you know, with using cal-hypo is the increased calcium level (some is good, but lots is bad) and the tri-chlor sends the cya through the roof and drops the pH.

When I worked for the co. in Va., we had bi-weekly deliveries of liquid chlorine to each pool (they all had 2 55gal plastic drums), though you can also look into the 5 gal 'carbouys'. I'd imagine that buying and transporting 'umteen' cases of bleach from Wal-mart would quickly loose it's thrill .

Pooldoc is probably your best resource for this question, but he's apparently having some trouble in his personal life (see the first topic here "Notes ..."), so I'm not sure that he's available to help right now (we can all pray that everything works out well for him!!)

As a last notew, Poconos uses all 3 types of chlorine durring a season, use the cal-hypo to get the CH where you want it and the pucks to raise the cya to where you want it and then switch to bleach for maintaining the cl, then just use the other types to 'tweek' the levels after heavy backwashing or refilling.

I hope that this is 'somewhat' helpful - if I can be of further help, all you have to do is ask! God Bless and good luck!

[EDIT] Go figure, no answers when I started my response, but 2 when I post (man I gotta get better at typing )

[Poolsean]

"..at 175,000 gallons, the pool is about 6 times the size of mine."
IF you have 5 people using your pool, that would equate to 30 people in the church pool. Reality is that you will have much more people using the church pool.
What ChemGeek lists are very important and it is necessary to first calculate what the approximate chlorine demand of the pool is.
The parameters I use are:
Pool Volume
Maximum bather load in a 24 hr period
Filter pump running hours per day
indoor or outdooor location?
flat pool or are there water features (such as waterfalls, slides, spray heads,etc)
peak water temperature

From there I can give you about how much chlorine you may need on the heaviest chlorine demand days.

Good luck.
(FYI: we did a church pool in the Atlanta area where the main house (residential) was a scaled down version of the White House and the pool area/club house was adjacent to the house. This too was about 160,000 gallons but I would estimate they had over 150 in the pool on a typical weekend. It's not too tough as long as you - as Carl D says - "stay ahead of your water")

[Sumo1]

Thanks for the responses. Please hang in here with me as I'm not able to go online every day. I'm working on getting the figures requested. The pool volume is 175,268 gal. It is a flat outdoor pool with no water features. There are 4 pumps running 4 sand filters. I expect they run 24/7 once started but will doublecheck that. With a low budget this summer, we expect to open it only for 6-7 weeks. Usage will be weekends only for Kid's Camp, Mission Work Camp, VBS, etc. I wouldn't expect the total # of people in the pool at one time to exceed 100 but will get other opinions about that and let you know if different. Temp is at the mercy of the weather but I'll ask whether anyone knows last year's high temp. Thanks---Hal

[huskyrider]

IMO, bleach is the best way to maintain any really large (100,000+gals) swimming pool.
I also have a really large pool, I only use bleach as my sanitizer.
This time of year I check my chemistry once weekly, during the swim season (Mar-Nov in Texas) I check them every other day.
I find it very easy to maintain.

I'll highlight some great advice posted here

"You WILL need to check your levels every day"
I suggest in the evening at closing
"I would tend to say run the FC closer to the high end of recommendations because of the bather load"

"Be sure that babies in diapers are NOT allowed in the water."
This is a MUST

"40+ commercial pools and all used sodium hypochlorite (liquid chlorine) with a peristalic feed pump. The pumps can be a real pain to get the feed 'just right"
All my commercial pools use orp controllers with peristalic pumps to feed bleach and acid from plastic drums.
The controllers are sensitive and the probes must be cleaned periodically.I could have one of these systems on my pool but choose not to.
I use a Taylor 2005K complete testing kit, this site also has an awesome test kit available.
My 13 yr old daughter does the testing now and I help her with determining how much of what chems to add.
You'll find that, once balanced, your pool should be easier than you might expect to maintain.
Many pool owners are intimidated about taking care of there own pool and choose to pay a service. I disagree with this completely, a knowledgeable owner will take better care of the pool than the typical service.

This site will give you some awesome advice on pool water chemistry.

See ya,
Kelly

[waste]

Kelly, damn good to see you here!! (I thought you'd lost intrest with this forum)

Hope all is well, and thanks for staying with us !!!!!!!!!!

Sincerly, Ted

[Poolsean]

KELLY! Hey man, I'm going to be out there for the Southwestern Pool and Spa show. If you're going to be available, please let me know. Love to take you to lunch or dinner, whichever you're available for.
We can talk about how salt systems can be used for commercial spas effectively. Glad to see you back also!

[huskyrider]

Thanks guys.

I really feel guilty, I've found myself piddling around in that other pool forum after work in the evenings, after I eat supper and go to bed I've missed checking in at this site. I've always enjoyed coming here and know that the members have always seemed to enjoy my unbiased replies too.
The other day was a complete rain day wash out, I checked in but could only find one thread I felt I should reply to. I'm going to make it a point to come in regularly like I used to.

Sean, I normally don't attend the shows but would love to meet you in person. I heard the regional show was in Houston this year but I don't know when it is. I'll Google it and give your rep a call to pass you my cell number and get yours from her.

See ya,
Kelly