yellow algae

[Watermom]

Not quite. Shock level for a pool with a CYA reading of 60 is 20ppm. If you add the third gallon it would bring it up to shock level.

[ronjorob]

added 3 gal chor then added another 24 hrs. later . still got algae. now not sure if it is algae or stain. i goofed in my chart i have a ig pool with gunite pebble tec.

[aylad]

You need to hold that shock level until the algae is gone, testing and adding more bleach as needed. Letting your chlorine yo-yo up and down like that won't ever let you get ahead of the algae and kill it.

Janet

[Watermom]

There is a thread in the notes and announcements section where you can give the corrections that need to be made to your Pool Chart Entry.

[PoolDoc]

If you'll look at the Best Guess page linked in our signatures, it will explain why, and give you the chlorine levels that you need to eradicate mustard algae. In your case, it will probably take 25 - 30 ppm sustained over a week or so, plus brushing. You'll have to get a K-2006 test kit (see test kit info page) to measure and control those levels.

There are other ways to do it, but they have other complications, too.

[ronjorob]

bleach is 6% concentrate and chlorine at orcharde supply is 10% and cost is not much higher

[Watermom]

If it is 10% sodium hypochlorite and a better price and fresh, they buy it. One thing I will tell you is that higher concentrated sodium hypo sometimes isn't the percentage it is advertised at especially if it isn't fresh. Here's a way to test the concentration of your bleach...I copied this from CarlD, one of the other mods, that had posted it a long time ago...

Put ten liters of tap water ( That's 5 soda-bottles full) in a 5 gallon bucket.

Test that water for chlorine using the FAS-DPD test to get a chlorine baseline (you may have some).

Then I take a 1 ml eyedropper full of the LC or bleach I'm testing and put it in the bucket and mix it up.

(1 ml in 10 liters of water is the same as putting 1 gallon of LC in a 10,000 gallon pool -- it's 1/10,000th. )

I then measure the bucket with the FAS-DPD test just like pool water. Of course, subtract any chlorine you measured in the tap water.

I use a glass eyedropper so it will hold up. Pharmacies sell them.