Bocomo - ""It's my understanding that BGA are photosynthetic and would also be slowed down by pond dyes that block the wavelengths they need to make energy just like FA.""
Algae and especially bluegreen algae (BGA) are not this simple. One cannot generalize and apply it to all BGA. This is a complex topic due mainly to there are so many species of algae - tens maybe hundreds of thousands. The smaller the organisms become the more species there are in that group. Not all algae including BGA are the same. We can't assume they all have the same requirements. Each species is unique and many if not most, are adapted to often a unique set of environmental variables; that is why they don't all bloom at once in the same conditions. Some algae are what we call generalists and can grow in a wide variety of conditions. Some algae species are indicator species and are very specific as to what they need to thrive. This is similar to fish. Carp are generalists and can grow in almost any water type, not true with say brook trout or other species sensitive fish called an indicator species. Invertebrate species are are similar in their wide range of environmental requirements that span all the species.
Yes some BGA are copper resistant although some other species belonging to other algal groups are also tolerant to various concentrations of copper. Some algae will thrive or bloom in higher concentrations of copper that kill all the others - they have adapted as tolerant or needing abnormal amounts of copper ions.
I am convinced bluegreen algae species are stimulated by various types of light wavelengths and intensities. The floating planktonic BGA usually prefer high intensity light. Bottom growing BGalgae often tolerate low light and some BGA I think can thrive on different wavelengths than green algae. Many algae in all groups can thrive in low light conditions. Beginning to see the 'rub'?
The BGA that Snrub is seeing in his black dyed pond could be thriving in the areas where the dye is less effective such as shallow water zones or on the surface. Or his BGS could be adapted to black dye better than a dye of another color.
Great explanation for us laymen Bill. An update on my algal situation of my main pond.
Early this spring I was getting some FA growing around the banks in shallow water that looked like it could become a nuisance. I had a little Cutrine granules left over from last year so treated the area from about 1-3' out from the bank. Did not put any granules right at the edge of the bank because I do not mind a little FA for the critters and fish larvae to use for cover as I have little bank vegetation yet. Ordered some more Cutrine Granules and black pond dye at that time (early March).
The Cutrine knocked it back and have done nothing since. Got a good planktonic algae bloom going and looked like I might not need the dye. Lots of water flow through with local flooding lately so that should cut the nutrient load down on the pond and I am crossing my fingers I am done with FA management for the year. We will see. I'll have the Cutrine granules and dye for next year.
Bob Lusk had chimed in on another thread about using dye that if you are going to use it for FA control do it early in the season, not later when the YOY larval fish need the phytoplankton to survive and the phytoplankton need an algae bloom to survive and thrive. I was glad to get that information as otherwise I might have used dye later in the season than I should.
An odd thing happened when I ordered my black dye from Rain Biologics. I kind of forgot about it and a couple months later wondered where my dye was. I emailed them saying I had never received it. They promptly emailed back and said they had screwed up a few orders and mine was one of them. They were going to ship my case of black dye out immediately and for my trouble at no cost also ship me a case of blue dye. I would have settled for an apology (mistakes happen) but they went beyond that and gave me a bunch of free product. I thought the company was trying very hard to keep pleased customers. I was impressed how they took care of it and without me pressing them or asking for any special favors.
With the free blue dye I may try mixing blue and black next spring should I feel the need to dye the pond. Ideally both cases will sit on a (non-freezing location) shelf and never be needed.
