I have historically used the blue dye in our small pond...it absolutely inhibits plankton growth. This has been our swimming pond as it's primary purpose so I'm OK with that...up to now the fish have been secondary.
This year's effort to reset that pond has changed my mind on that particular front. As of now I haven't applied any dye to it, and probably won't for at least a few years.
I really like the way the pond looks dyed but am not willing to sacrifice the nutrient foundation it prevents, at least not now.