Ok, Probably not as ground breaking as the title makes it sound, but hey, at least your reading this thread right now! Anyway, this little trick is pretty well known but I thought it was worth sharing for some of the newer guys just in case. Anyone that has ever gotten a snail caught in your drain line, this is for you,(and for those with overflows). Make a simple acrylic cover to fit over the top. It prevents snails from crawling up and over the overflows and into your drains. It also has the added benefit of blocking light from entering the overflow area reducing algae that can slowly clog the overflow over time.. My tank has been set up for seven months and has zero algae in the overflows which is generally an ideal place for the growth of hair algae. so... nothing new or ground breaking. just a simple headache saving tip... here is a pic of mine!