I seem to have an odd problem. I cant seam to keep a Pleco (common) alive if they are small. I have 3 over 8" long one is about 12" (I have Never actually measured him) my trouble is any time I have ever had one under 3" they die. Nothing else in the tank is effected just the smaller Pleco. I vave had another pleco in th tank on one occasion and he was uneffected and they have also been solo. The larger ones are fine and actually very active but the small ones have got me truly frusterated. Any Help would be appreciated.