B.C. as in botanicare? well, i do use their line, and i used to have a brown algae problem. it can be solved a couple ways.
1. block light from any surface that contacts nutrient solution. this includes using black or other light-proof reservoirs, black tubing, etc... if you grow in DWC buckets, the light can easily leak through the hydroton and grow algae. if this is your case, cut 1'x1' square of B&W film, cut a slit from the center of the square to the edge to go around the stem. you can tape it if it falls off easily, but i haven't experienced this.
2. add beneficial bacteria. as stupid as this sounds for hydro, certain bacteria and enzymes will eat the algae, along with dead roots and plants material. the added benefit of beneficial bacteria is that while they are present in the reservoir, they prevent pathogenic bacteria and fungus from forming by competing with them for food. avoid using Mycorrhizae in hydro systems, as they are ineffective.
3. use hydrogen peroxide. it's a common practice to add H2O2 to your reservoir every couple of days to maintain a sterile reservoir. this will kill everything in the reservoir, except the plant. this is my least recommended method, as it will also kill any beneficial bacteria in the res which can invite diseases. i do not personally use peroxide in my system, so i cannot advise the concentration, but there are many threads that do. search "h2o2"
hope this helps
