I can't seam to keep anything other than Pleco's in my tank with my 8 Bleedingheart tetras. Other tetras, guppies, and well any thing the same size or smaller, ends up dead. My tank has 8 tetras and two dwarf plecos. the plecos are both about 4 inchs now and my tank is a 72 gal. I experemented by putting one of the smaller tetras in with a fighting fish, in the fighting fishs tank, and the fighting fish instantly backed down and hid from the tetra. Anyone heard of anything like this?