Ok. Your shock is simply strong bleach. Bleach is 8.25% sodium hypochlorite. So, you can use what you have. I estimate your volume to be about 13,000 gallons. So, each of those gallons that you have (assuming that they really are 12.5% and the strength hasn't degraded although that is common) will add about 9.5ppm of chlorine.

This evening, go ahead and add 2 gallons of the shock. This is higher than your kit's chlorine test can measure but you can use the chart at this link to interpret off the chart OTO results:> http://pool9.net/oto-chart/

It isn't going to stay that high for long so you'll need to continue to add shock to try and keep your chlorine in the dark yellow range. If your pool is as swampy as you say, you may find that by morning, you have lost a lot of the chlorine. That is good. It will mean that is has been busy overnight killing stuff. You may need to add chlorine a couple of times per day although adding it in the evening is the best time because it allows all the chlorine to go to work oxidizing stuff with none of it being lost to the sun. However, in a pool with low CYA like yours, you may have to also add some during the day to keep some chlorine in there.

Once you get your pool cleaned up, you'll need to add some CYA. You can either do so by using some dichlor for awhile or by just adding some CYA separately. A lot of places are selling blended dichlor which you don't want. IF there is a Sam's Club near you, they sell some good dichlor that you can use. If you buy their 1 lb packs, any that you don't use can be saved until next season. http://www.samsclub.com/sams/shop/pr...oductId=108822 If you would rather just add some CYA separately, let us know and we can help you figure out how much to buy and add.


Since you have a CYA test in your kit, instead of ordering a K2006 kit, if you will just order a K1515 add-on kit, it will give you the chlorine test that your kit doesn't have that allows you to measure chlorine readings past 5ppm. It is also available through that same link that I posted above.

Just get one jug of distilled water. No need to buy bleach today although once your 5 gallons are gone, you'll either want to buy bleach or buy more of the shock. Figure out which one is the better buy. I will tell you this, though. Higher concentrations of sodium hypochlorite that are often sold at pool stores have often degraded and are therefore not really the strength the label says. Walmart's generic bleach has a high turnover rate and is more likely to be fresh.

By the way, don't run the CYA test anymore for now. It isn't going to change unless you start using a stabilized form of chlorine (which means it has CYA in it) or unless you add some directly. No reason to waste the reagent.

I'd be curious to have you do a calcium hardness test on a well water sample.

Keep us posted how things are going and if you have more questions, we'll be here!