I have battled red slime algae on my sand off and on again for about a year as well as a few other fellow reefers in this area. The local tank maintance guy in town told my friend Nancy to put Erythromyacin in a small dose in her tank and the red algae would be gone in two days. Out of frustration..she tried it!! It was gone almost overnight. Norm, my friend, said what the heck and put it in his reef tank and it was completly gone in two days. Veda, the fish store lady dumped it in her tank and it was gone over-night. I was petrified to try it because I have a fully stocked 180 gallon reef with thousands of dollars worth of corals in it but I went ahead and jumped. I put four Erythromycin tablets in and woke up this morning and the red algae is completly gone!! No sighn of it at all and my corals are all fine. Has anyone else done this with success or failure?? Lets hear the stories. I can't believe I looked at that ugly stuff for months and it is gone after one day!! :rollface: Kimmy