Help! We started a 37 gallon tank about 2-3 weeks ago, the water tested perfectly, but we had 2 angelfish who wouldn’t eat. Long story short, 6 tiger barbs died, a baby angelfish died and the first big angelfish died just yesterday. We had another big angelfish left and this morning he is completely gone. The other fish in the tank are 3 gouramis, 2 tiger sharks, 1 pleco and 5 fiddler crabs. Did they all just eat him alive??