Join Date: Mar 2014
Location: Vancouver Island
I'm as miffed as you both are. But I did find this on the fish lore forum.
"Allelopathy describes the production of chemicals by an organism that adversely affect another organism and/or advantageously affect itself. In the case of plants, these chemicals (called allelochemicals) are often readily produced to inhibit the growth of other plants or alage, or to prevent animals from eating the plants. Plants depend heavily on allelochemicals because they are unable to defend themselves in a movile way (e.e. they cannot run, move or fight in the traditional sense). In nature, although these chemicals may be produced in abundance, they are often diluted in effect where a single plant is concerned. Only when a particular species is grouped over a wide area can a noticeable effect be seen. However, in the enclosed environment of the aquarium, allelochemicals can quickly build up, with various effects on some plant species. For example, it is not unusual for an aquariust to have problems keeping certain species of plant, even though the lighting, temperature & water quality are at ideal levels, & there is an abundant supply of nutrients. Often. the reason for this common occurrence is that another plant in the aquarim is producing particular allelochemicals that inhibit or prevent the growth of the 'problem' plant. The allelochemicals produced by some aquatic plants have a particularly adverse effect on floating plant species and algae. This is one of the main reasons why a well-planted aquarium may not show signs of algae blooms, despite high nutrient levels & strong lighting. Although some information is available relating to specific plants and the allelochemicals they produce, little is known about the process of allelopathy, so it is impossible to produce a list of compatible plant species. In most cases, it is a combination of chemicals, rather than a single allelochemical, that has an adverse effect on plant species. In any case, it is worth being aware of the process when keeping aquatic plants, because it can sometimes explin an inability to keep one species of plant while others thrive".