I just got a new pleco and added to my 75 gallon it was a small common pleco not even 4 inches yet and I came in today turned on the light and found it dead. I had to do a water change as my water levels were out of wack I also added a bamboo plant. Advice? Questions to help me figure out why. My other pleco that is maybe 5-6 inches is perfectly fine besides being a little fat.