Darkside of the Pool said:
But are there any known effects for Bromamines?
On a completely other topic, thanks to CaOCl2, I've put my hands on a document called ''Biolabs_Responds_to_phosphates.pdf''. It's an extract from Aqua Magazine, August 2010, where Biolabs DESTROYS the claims made by pool store (which were taught by other members of the industry). I took the time explaining why phosphates weren't really a problem to one of my boss, the message spreaded and we stopped affiliating with Natural Chemistry (although we are still affilliated with Ocean Spa, their pupil, I mean, their SWCG for spas are neat).
Monobromamine is presumably a reasonable sanitizer, unlike monochloramine. So one doesn't care as much if one has bromamines from a sanitation point of view, but they still smell so it would be good to know when they are there and unfortunately the DPD tests can't distinguish it (i.e. the bromamine reacts directly with the DPD dye just as chlorine and bromine do).
The other downsides to bromine are higher cost, lack of protection from breakdown from sunlight (though it breaks down more slowly than unprotected chlorine), being somewhat weak at oxidizing bather waste (so one occasionally needs to shock with chlorine or use non-chlorine shock if the water becomes dull or cloudy) and having disinfection by-products such as brominated organics (brominated trihalomethanes, THMs) that are more hamful than their chlorinated cousins. That's more of a concern for high bather load pools (and possibly for residential spas where bromine is more commonly used).
That Biolab document has some inaccuracies in it if it is the same as the "Preventing Algae Growth" Word file from Biolab Technical Solutions written by Karen Rigsby. The paper talks about different kinds of phosphates, distinguishing between orthophosphate which is what the phosphate removers remove vs. other phosphorous containing compounds (they don't say it, but most of these are organic phosphates; some are polyphosphates) and how the latter can be used by many species of algae that have enzymes to break down these organic phosphates into the useful form. What the paper didn't say is that the uptake of such organic phosphates is much slower than that of orthophosphate and limits the rate of, though does not completely prevent, algae growth. For example,
this paper indicates that bacteria utilize organic phosphates much more than algae (i.e. the fastest algae growth comes from orthophosphate).
This paper has similar conclusions where essentially it is the more efficient bacterial conversion of organic phosphates and excretion of orthophosphate that can provide this faster-uptake nutrient to algae. In a pool, however, bacteria are killed very quickly with chlorine so this mechanism isn't readily available -- that is, bacteria aren't converting organic phosphates rapidly to orthophosphate so algae are left to do that on their own, much more slowly. Therefore, concluding that orthophosphate removers (such as lanthanum chloride) do not at least slow down algae growth doesn't make sense and is inconsistent with this and many other scientific papers I haven't listed here (but that I've read).
The BioLab paper does talk about algae storing phosphorous in their cells, but this isn't the point of phosphate removers anyway. They aren't intended to kill existing algae, but only to slow down their growth. With chlorine in the water at sufficient levels, algae is killed (and largely oxidized). PolyQuat is very similar in that it isn't very effective in killing algae in a full-fledged algae bloom. It is far better to use lots of chlorine for that purpose and, if one wants, to use PolyQuat to inhibit algae growth thereby allowing for lower FC/CYA ratios to still be able to kill algae faster than it can reproduce. This is why I put phosphate removers in that same category of algae inhibition, but that chlorine itself is what does the real work of killing the algae. Most algicides, except for copper (which can stain, of course), aren't effective at completely killing algae and even copper requires chlorine to oxidize the algae to clear a pool (unless one uses filtration/clarification to do so). Phosphate removers aren't registered with the EPA as algistats mostly because that costs extra money for little purpose since one can easily market "no phosphates, no algae" though that is, of course, misleading.
The standard phosphate tests only test for orthophosphate, not for organic phosphates. However, testing for and reducing orthophosphate is still one way to slow down (though not necessarily stop) algae growth, thereby allowing lower active chlorine levels to finish them off. I am not a fan of phosphate removers, but I'm not going to say that they are completely ineffective.
We don't promote algaecides in general, let alone phosphate removers, because they aren't needed if one maintains sufficient chlorine levels. Since one needs chlorine anyway for sanitation and oxidation, it might as well be used for algae prevention as well. However, if someone wants more insurance in case they want to have lower chlorine levels or accidentally forget to dose with chlorine, then there is a wide array of choices available at extra cost. We prefer PolyQuat 60 or the use of 50 ppm Borates for that purpose because these have minimal side effects and usually reasonable cost.