I just woke up this morning and found 8 dead fish in my 29ga tank (3 Bosemani rainbows, 1 Red Irian Rainbow, 2 turquoise Rainbows, 2 Green Tiger Barbs). The only remaining fish are 2 female Red Irians, a baby pleco, and a SAE. The tank is heavily planted, eheim ecco 2330 filtration, Hagan CO2...