algae

[aylad]

What are you using to test? Are you using strips or a drop-based test? Keep in mind that test strips are not accurate enough to help correct a problem--they give you a ballpark, but you really need accurate numbers to fix problems. If you don't have a drop-based test, you need to get one.

Once you have algae growing, you have to maintain a shock level--key word MAINTAIN--until you have killed the algae. With your CYA level, you need to get your chlorine up to 15 ppm and keep it there by testing and adding more chlorine 2-3 times daily until the algae dies. It won't help to shock it once, then let your chlorine come down. 10 gallons of 6% bleach will raise the chlorine in your pool to approximately 16 ppm--but if you haven't add any since then, you're not going to make any progress against the algae, since the chlorine is being used up in the battle against the green stuff.

Bleach will sometimes cause a temporary rise in pH, and high chlorine levels will often cause the pH test to give falsely high results. If your slide is turning yellow, and you are using test strips to test your water, I strongly recommend that you have the water tested using drop-based testing to make sure you really know what your chlorine level is. If it's not at 15, then you need to get it there and hold it there to kill off the algae.


WalMart bleach (generic) is 6% sodium hypochlorite (chlorine). Clorox is also 6%, I believe ( you can look at the label to confirm). However, clorox has started adding another ingredient to the bleach that is designed to help lift stains, but can appear in pool water as a white sediment on the bottom. WalMart bleach is cheaper and has no added ingredients (as long as you stay with the plain ultra bleach and make sure you're not buying the stuff with the scents added--you don't want that).

Janet