algea in pool

[tara15]

ok. so i first added about 4 pound of baking soda to the pool and retested about a half hour later. the readings are as follows

fc 10
ta 120
ph 7.2
cya 100(still)

i added about 2 gallons of bleach for now since that is all i have on hand until i go to the store. do you still think i need 5 gallons? also, we noticed when we didnt have the pucks in the floaters, the algea problem got worse and we were shocking more. how often should i add bleach to the pool? when is it safe to go back in the pool?

[Watermom]

You say "still 100" when referring to your cya reading. It isn't going to come down - unless you do a partial drain. If you use more pucks, it is going to continue to rise which you don't want. Take a look at the Best Guess chart in the following link.

http://www.poolforum.com/pf2/showthread.php?t=365

Yes, you need to shock up to 25 since your cya is so high or you won't get rid of the algae. How often? Test at least 3x a day (more won't hurt!) and EACH TIME add enough bleach to get your cl level back up to 25. The key to killing algae is to sustain the high reading and not let it yo-yo up and down. In a pool this size, each quart of 6% bleach will raise the cl by 1 ppm. Also, run your pump 24/7 for now. After your algae problem is gone, you'll need to keep your cl between 8-15 all the time because of your high cya or you'll have another algae bloom.

Another option is to do a partial drain and reduce your cya to about 50 which would be ideal. It is up to you. Partial drain or just run higher than normal cl readings. Either way will work - it is up to you.

Your ph and alk are OK now. If your ph drops any, you'll want to use Borax to raise it instead of baking soda.

[tara15]

the only reason i said still 100 for cya was that the test strips said that the ph and alkalinity affected the cya reading. also, where can i get test strips that give you a number higher that 10 for free chlorine? do i have to buy them at the pool store? i also have a dog who like to swim in the pool. is it safe for her to swim if she doesnt mind slightly green water or should i wait?

thanks

[Watermom]

We don't recommend teststrips because they aren't very accurate. Most of us use the kit that Ben sells at the sister site to this forum www.poolsolutions.com. It WILL test high cl levels which you're going to need to be able to do if you decide to keep your cya of 100. At the very least, buy the 5-way drops based kit at Walmart for about $15. It won't test cl higher than 5, but you can dilute the sample and make it test higher. However, just be aware that with each dilution, you do lose some accuracy. To dilute - take one part pool water and two parts distilled water, mix them together and then test as usual. Then multiply the result by 3. (If it were my pool, I'd do the partial drain and lower cya to 50. Just my opinion.)

About the dog - dogs swim in green ponds all the time so............. but, I probably wouldn't let it swim in the pool when it had been shocked so high.

Hope this helps. Keep us posted how things are going.

[tara15]

ok here we go again....

I took some water to the pool store for analysis. these are the results

fc 5(thats all they go up to so it could be higher)
ph 7.6
ta 150
cya 50

so now what? i added 2 gallons of bleach, waited a while and brushed and vacumed the pool. do i wait and see now?

thanks

[Watermom]

Your cya level is drastically different than before. We are always leery about pool store readings and test strips so I don't know which one to believe. Also, since it could be 50, I am now skeptical to tell you to shock up to 25 as we suggested before when we thought your cya was 100. Can you go and buy the drops based kit I suggested above and test the cya yourself? We put more faith in test results that we do ourselves. You should also run the cl test yourself and use the dilution method I described above. Then repost and we'll go from there.

[tara15]

ok....

i got the test kit with 5 drops and the strips as well to compare...i know you dont like the strips.

here are the results

total chlorine(by diluted it the way you told me to) 15 or even higher
cya 70
ph 7.2

test strip
free chlorine over 5
ph 7.6
ta 150
cya 100


ok so now what?