My tank is a 48" long 90G. i have a 36" bubble wand in there, i think thats enough oxygen.. what do you all thing? i have never tested the exact oxygen levels though... The Jd's are very skittish in my tank, and just hide behind rocks, theyre not aggressive from what i noticed, but i havent seen my tank in about 4 days no or 5 even... but there are NO i repeat NO cuts on him, nipped fins, cloudy eyes, ich spots, no scrapes.. only thing messed up is he breathes with one gill side only and his jaw is crooked.. Ill take some pictures this w/e. when you all can see what i mean, maybe we could figure this out faster.. and i hope its not a parasite or anything.. i feed him, worms, bloodworms, dillies, and sometimes he eats pellets.. also he likes lil crickets and other bugs.. but thats only when i find him some.. and it has been awhile.