before we go into details: what would the pH of your "untreated" water be ? (as this is the most important factor for "chlorine"-solubility)
if we're talking natural seawater, it should be around 8,0 , i.e. a littel on the alkaline side
this way, chlorine should have a chance to dissolve in water*)
, whereas with a pH at 7 or even lower, indeed you'd run into some problems.
the talk about phosphates and nitrate being the problem sounds like complete rubbish to me, if they're really meaning it (i.e HPO42-
) : these ions wouldn't consume elementary chlorine (Cl2
) under +/- neutral aqueous conditions in any meaningful way.
on the other hand, sometimes "phosphate, nitrate" are just shorthand for "sum total of organophosphates and organic nitrogen compounds" - meaning (pls. excuse me: its just for clarification purposes, no offence intended) that someone took a leak in the pool, for example, and now the usual suspects like urea would be in the water.
these in fact would be attacked by the chlorine (this is the whole point in adding it to the water: that it attacks organic material, bacteria and thatlike in a New York minute) and would consume it.
but then again, one foot downstream of the generator...
in my opinion, it would take the situation at a sewage treatment plant with your water to bring chlorine to zero in such brief a contact time, and I am convinced that the water in your pool isn't anything like that
for the time being, my bets hence are on the pH being low, and that's an easy problem to address, should it be so
the solubility of chlorine - gas in neutral (or even worse: acrid) water is very poor.
with (even slightly) alkaline water, chlorine will dissolve forming chloride ( Cl-
) and hypochlorite (OCl-
) as products, with hypochlorite being the active species for your purposes
+ 2 OH-
thereby improving the (indirect) solubility of the chlorine by several magnitudes