I'm back into this old and renewed topic. The newer information is interesting. First to answer an earlier question by ewest:
"What effect does the proper use of registered pond dye {that containing the correct acid blue and acid yellow content} in a pond have on the plankton base in the pond? Does the pond dye block out those light wavelengths that are necessary for plankton growth?"
ANSWER: Lack of light to the plankton generally inhibits it. The more the light is reduced the less the plankton grows. It is hard to put a number on the amount of plankton reduction due to several factors such as: concentration of dye, species composition of the plankton, natural stains in the water, water fertility variations, amount of suspended detritus (natural), and water chemistry. IT ALL DEPENDS.
Advanced reading.
Two kinds of plankton: phytoplankton - tiny, suspended 'free floating' plants in the water column, and zooplankton - the animal part, comprised of microscopic ones and those up to sizes visible with the eye. This includes one celled animals (Protoza), rotifers, and the larger more 'free swimming' crustaceans. simplistically, the zooplankton mostly generally feeds on the phytoplankton group. Bacteria and tiny organic particles are also commonly eaten by many of the zooplankton.
Lack of proper light reaching the phytoplankon generally inhibits its growth and development. The less light it receives the less it grows; similar to terrestrial green plants. As with terrestrial plants some phytoplankters are adapted to grow well in shade or low light. Some of these may not be good or edible food for zooplankton.
I generally think that when dyes are used at label dosages it reduces the plankton growth (overall natural productivity) by about 50%. The reduction may in reality may be somewhere in the 30%-60% range. I am currently conducting a few tests on this topic. More information will follow. If I'm successful, watch for it; probably in a Pond Boss article.
It was stated that the Yellow 23 is not very stable in aqueous solution and it readily percipitates. I am pretty sure this is why Aquashade brand utilizes Monoethanolamine (<1%)in their product. Monoethanolamine is a emulisifier and dispersing agent to keep both of the dyes dissolved and in proper suspension. I was told long ago by Aquashade representatives that the yellow dye is an important component to properly filter out red and orange wavelengths to achieve effective suppression of plant growth i.e. photosynthesis. Just becasue the water appears blue does not mean You are getting good or effective reduction of both red and orange wavelengths that are necessary for photosynthesis of green plants (weeds, FA, and I assume most of the phytoplankton species). The presence of yellow 23 and monoethanolamine in pond dye may be worth a little extra expense if you are using dye / colorant to achieve plant control.
Commentary. I would expect that you could contact the pond dye manufacturer for the PDC (pure dye content) and total contents / ingredients. If they will not provide that information I would be very suspect of the product and maybe the knowledge and/or integrity of the manufacturer.
Last edited by Bill Cody; 03/12/14 09:37 AM.
