Hello- we are having a pool party this wknd and was wondering do folks increase FC prior to the party. CYA is 40 and FC currently 4.5 (all other numbers look good). What's best way to increase?
Increase FC for pool party
- Thread starter will
- Start date
- Jun 22, 2014
- 47,726
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
If you want to take your FC up a couple notches an hour or two before the event that should be okay. No need to get carried away though. The most critical check will be after the event to replenish the FC that gets depleted from all the swimmer's load. Just augment your SWG with some regular liquid bleach. Make sure it's not splashless or scented.
Yep, I add some bleach before and after a big party. It is quick and easy and gives FC an instant bump. A couple ppm above target, or up to half of shock level. For CYA 40 that would be up to 8 ppm, pre-party. The critical thing is to make sure that FC doesn't drop below minimum, ever. With FC below minimum the pool becomes unsanitary.
I brought my FC up to 5 (CYA is under 30) before my party (some time in the morning...the party started at 2) this last weekend. I checked it that night (11pm?) and it was below .5! Luckily we all survived intact but I'm interested in how to prevent this from happening next time we have a lot of swimmers. Would having more CYA help? (I know it's low right now).
I believe most average pools use 2-4ppm FC per day. On a party day, with a high bather load (one of the biggest non-algae demands of FC), you are smart to prepare with an extra dose at least 30 minutes, pump running, before the party. Since it is generally considered safe to swim as long as the FC is below shock level for your CYA, which for CYA 30 is FC 12. Your daily consumption + pool party totaled roughly 5+ ppm FC. Since the CYA chart says the minimum FC at 30 CYA is 2ppm (with a target of 4ppm FC) and we know we have the room to go up to 11.5 FC, we want to add enough to enjoy the day safely, and still end up above 2ppm, even better the target at 4ppm if we have any dead zones, history of algae issues, or other risk factors for algae. So all things considered in your case, I'd assume my pool parties of similar size require an addition of 6ppm extra, for a pre-party test of 6+4= 10ppm (not to go over 11.5 even for big parties since it could be unsafe for swimmers and not worth the risk). Remember this does not mean adding 10ppm, since you're likely to already have 2-5ppm in there if you're maintaining it regularly. Test and use pool math to get to trouble free results. Just my two cents, and if your party is a lighter one, just going to 7.5-9ppm FC might be about right.
If you really want to be prepared, and like testing, you can test before the party, 30 mins after your pre-party FC boost, and then after the party. Add this in your pool journal that you keep with your test kit and not the temperature, sun, and number of bathers, whether they had sun tan lotion on or not, and if there were any animals in the pool. Stuff like that will help you, over time, have some very, very accurate predictions of FC demand under similar situations. Is this necessary? No, not at all, but some people do it and like doing it.
If you really want to be prepared, and like testing, you can test before the party, 30 mins after your pre-party FC boost, and then after the party. Add this in your pool journal that you keep with your test kit and not the temperature, sun, and number of bathers, whether they had sun tan lotion on or not, and if there were any animals in the pool. Stuff like that will help you, over time, have some very, very accurate predictions of FC demand under similar situations. Is this necessary? No, not at all, but some people do it and like doing it.
