The turbity looks like classic clay suspension. I'd wonder if the carp reproduced and are stirring up the bottom looking for food...this would also explain them eating FA...trying to eat anything to avoid starvation.
After some brief research, I found nothing at all suggesting the israeli carp eats any form of algae as a direct food source. Regardless of what any one says to the contrary...CC, lmb, grass carp nor israeli simply do not eat FA intentionally and will not control FA by consuming it (unless they are starved). None of the fish listed eat FA intentionally. with the exception of otherwise being starved, any FA they may consume would be ingested the same way a child would eat dirt after dropping a sticky sucker on the ground, picking it back up, then eating the sucker again (dirt included).
As ewest pointed out, turibidty will block the needed sunlight for any plant growth to happen...An over abundance of bottom feeders would increase the turbidity and in effect, prevent plant growth by accident, not by intentional consumption. I too would be interested in knowing what the clarity is of the water.
This breif, straight-forward and blunt article sums up the problems and misconceptions about israeli carp...
Using carp..... 
