I have a 29 Gal, freshwater tank, semi-planted with a HOB Aqueon filter and canopy lights T8/15W and a LED light bar (white/blue). The water stays at about 76* and have a bubble want for aeriation. The ph is about 7.6, amonia was about .5, but just did a partial water change, nitrate = 0 and nitrite = <30. It's been setup for about 6 months. I kept 2 Koi Angels, 1 Marble Angel, 1 Black Angel, 2 German Rams and 8 Fancy Guppies. Last week I noticed that the tails on the guppies were getting frail and parts of them were missing. I figured I have tail rot. I was getting ready to start some treatment for it, but last night while I was staring at my tank I saw the bigger angelfish take a bite out of the tail of one of my guppies. I went upstairs for 30 seconds and by the time I came back all four of the angelfish were eating the one guppie's tail. I then realized that most likely the culprit of the guppies tail tearing were the angelfish. I quickly removed the guppies and placed them in my little spare tank where I keep a bule betta. I realize now that angels get really big and my 29 gal will not be big enough to keep 4 of them. That is besides the point thou, I will have to make arrangements to donate them shortly. My thing is, is it normal for angels to attack guppies like that?