ok so heres the story, i built the tank in dec 11, added fish too soon and they died (my fault) added fish again in jan, (volitan lion and snowflake eel) about 10 days later i added the dog face puffer, after a couple weeks they showed signs of ich and the lion was getting cloud eye so they went into hypo saliniy about 3 weeks later i added a dwarf lion to hypo and they stayed there for another 5 weeks or so and they all looked great except for the volitan lost an eye. during this time the display had no inhabitants except for the growing number of little critters, i fed the tank a bit during this time. all 4 fish went back in around april 10th and looked great and ate lots, during this time the puffer constantly sifted the gravel (about 15 hours a day it looked like) and ate more than i thought a fish could eat , they ate mostly frozen shrimp. the dwarf lion would only eat live things ( i tried to feed him off the stick but he would have none of it) after about 3 weeks of this i decide to install a sump, and i think all went well and stuff is growing. about a week later i see that the puffer is getting spots (figured it was comming from the gravel) so i watched the others closely and they never did get spots, so after another week he went in the 10 gallon hospital and started doseing with kordon rid ich plus (formaldihyde). and it looked like he got completely better, during this time the volitans other eye stared getting cloudy a few days later the dwarfs eyes started getting cloudy too, a couple days later they were both weak and lost most of their color so they went in the hospital too and died within 12 hours, during this whole time the snowflake has looked and acted completely normal and is still in the main tank. i dont test my water much, but after the puffer went to the hospital i started every day for nitrates and a couple times for ammonia and nitrite (both at 0 or close) the nitrates were at 80 or so with an api test kit i did 20 gal water changes for 4 days and i put in a reactor with old nitrate remover /phosphate remover and carbon the nitrates went to 40 then to 20 the day the lions died. after the lions died the puffers eys went cloudy he lost all his slime and died about 3 days after the lions. the skimmer pulls about 1 cup every 3 weeks but the fish wernt in there very long. so i still dont know whats wrong. if antbody needs any more info .,., just ask. thanks everyone!