Quote Originally Posted by waterbear View Post
Actually, both the inorganic ammonia products (such as yellow out) and the sodium bromide products work in the same way. They convert the chlorine in the pool to either monochloramine or hypobromous acid (bromine sanitizer), depending on whether you use the former or the latter, and in doing so take the CYA out of the equation. This is equivalent to having a MUCH higher ACTIVE FC level than you have. They are useful if your CYA is high (which is usually when pink algae starts) You CAN kill pink algae with plain chloirne but it takes VERY HIGH levels, higher than even mustard algae.

BOTH inorganic ammonia and sodium bromide product create a hugh chlorine demand after their use to destoy the sodium bromide or monocloramine that is formed so in this repect they can both be a cure worst than the disease. The only difference that the inorganic ammonia proucts have is that monochoramine does offer a bit of protection against UV light so the monochloramine might allow the chlorine to stay in the pool (but it will be in the form of CC).

I noticed that you are using trichlor. I am betting that your CYA levels are high. That is the reason you got pink algae in the first place. If you maintain your water chemistry properly, including CYA levels, then pink algae is not a problem in chlorine pools. IF you post a full set of test results I bet we would find them interesting.

When the proper amounts of hypochlorous acid and the inorganic amonia (Yellow Out) react in the proper moderately high pH one atom of chlorine is transfered from the former to the latter and the monochloramine is formed. If this species is more effective in oxidizing organics than HOCl this is fine, however, where's the higher chlorine intake? You simply made your available chlorine more "potent" because the NH2Cl is more active than the HOCl.
Maybe what you mean is that further superchlorination will transform the residual monochloramine to di and tri chloramines, and these, in turn, have to be broken down by further superchlorination as well. But this should be a one time process. However, since the monochloramine does the job on the organics, there's no need to continue and chlorinate it because the end product,once the chlorine atom of the monochloramine did its job, is harmless. Did I miss something? If you have links to the underlying chemistry please post.