I have the 2009 "CPO® Handbook, National Swimming Pool Foundation®" with front cover title "Pool & Spa Operator™ Handbook" right in front of me where on page 83 it talks about phosphates and nitrates being nutrients for algae, but nowhere does it even refer to phosphate removers (that's something I suggested they do in the future). Instead, they end with the following:
Since all the nutrients that algae needs, including phosphate and nitrate, are commonly available in pool water or are stored within algae, it is very important that disinfectant residuals be maintained at all times to prevent the growth of algae.
So when you are going to be referring to sources to bolster your argument, you should actually make sure they are truly consistent with the points you are making. In this case, they are not though I believe that is flawed and that the manual should refer to phosphate removers as another alternative to using algaecides when one is unwilling or unable to maintain a sufficient active chlorine (hypochlorous acid) level (i.e. FC/CYA ratio). In fact, the first paragraph in the Algicides section of the manual on page 82 states the following:
Disinfectants that chlorinate or brominate the water kill and prevent the growth of algae. Algae (and bacteria) prevention has driven more commercial facilities to install automatic chemical feeders, controllers, and probes to maintain adequate disinfectant levels at all times. Facilities without these mechanical systems are at a greater risk to have algae grow, since pool water almost always contains the nutrients algae need and there are likely times when the disinfectant is absent.
3 ppm FC would be OK if the CYA didn't get much above 30 or 40 ppm, but in pools that use stabilized chlorine, the CYA keeps increasing. High bather load commercial/public pools have most of the chloirne loss from bather load rather than from sunlight so have little need for a CYA level higher than around 30 ppm so there really is no excuse except that many such pools are unfortunately not using unstabilized chlorine (e.g. chlorinating liquid or a saltwater chlorine generator). Again, we've got tens of thousands of residential pool owners who manage their pools without phosphate removers, algaecides or other products -- just chlorine alone to control algae growth regardless of phosphate and nitrate levels. Because most chlorine loss in such low bather-load outdoor pools is from sunlight, the CYA level tends to be higher, around 50 ppm or so up to 80 ppm in sunny areas and in pools using SWCGs, BUT the FC level is raised proportionally relative to the CYA level -- that is the key to keep the same active chlorine (hypochlorous acid) level.
If you find it easier to use phosphate removers or algaecides at extra cost, then that's perfectly fine to do. Just don't fool yourself into thinking it is the only way to prevent algae growth.
By the way, when you refer to Ezi-Chlor, are you referring to the Clearwater Ezi Chlor peristaltic pump for automatically dosing chlorinating liquid or bleach or are you referring to Ezi-Chlor which is granulated Trichlor? If the latter, then for every 10 ppm FC you add, it also increases CYA by 6 ppm. That would not be keeping your CYA low unless you had significant water dilution. According to this MSDS , the product is a combination of Trichlor and borates where the latter helps balance the pH, but also accumulation of higher borate levels (around 50 ppm) is an algicide that you could instead separately add either from a combination of 20 Mule Team Borax and acid or from boric acid.
Also, you refer to having water with algae turn cloudy when you shock with chlorine as a bad thing, but that's what ANY chlorine source will do since it bleaches out the chlorophyll in the algae and then the algae needs to be further broken down or filtered out. Stabilized chlorine isn't the cause of that specifically. Cal-Hypo can cloud the pool if it is already saturated with calcium carbonate (e.g. a plaster pool).