As far as the dye, I would go with what the preceding responses are. It's obvious it would reduce food production by decreasing sunlight, but there are pros and cons.
I may be using it in the future in a couple of very small static ponds to keep weed growth down. One is only 25 by 30 feet, which I use as a nursery pond for fingerling fish, to grow them out on feed until they are big enough to go into a much larger pond with very large bass. The other will by a 50 by 40 pond that I will grow feed trained male only bluegills. Both ponds will be fed ponds so there is no concern with suppressing the food supply. I could fertilize, but in such small ponds I believe it could be possible to easily overfertilize and the feed and wastes from the feed will probably add enough nutrients as it is. With all the nutrients it would just be a matter of time before the birds brought in invasive weeds.
As far as bacteria, I had been using it in my flow through trout pond, but have discontinued as frankly I can't afford the steep price anymore. I have not used it for a month and my water never looked better. So who knows -- maybe we are getting a snow job with this bacteria. We really don't have any independent tests - so the manufacturers could be telling us anything.
