I would be much more concerned about why you're keeping tropical fish (Endlers and Plecos) with a newt. In addition to being tropical, plecos have large defensive spines, as well as powerful suction mouths, both of which can harm a newt. This is a dangerous combination.
I wouldn't keep any fish at all with newts. The only newt I have that has a chance at a regular meal with fish would be my Paddle-Tail. That being said, the only fish I would put in would be "feeder" Guppies, or Fat-Head Minnows. These options contribute less fat, and more crude protein than any other fish "meal". I know(or at least it seems) the fish were not intended as food, but even display fish can injure and kill newts of any kind, big or small. Once a neighbor of my grandparents tried to keep Eastern Newts with 2-3 goldfish in a decent size enclosure. In less than a week the gold fish had stripped all the toes off, and were starting on the tail and throat. I was horrified and never attempted to try any fish combinations because of the result witnessed...Just wanted to warn you, bad things can, and inevitably will happen...Best of luck!
The algae wafer should pass through quickly I'd assume, being that there is really nothing to contribute dietarily. If the specimen bloats, I'd try to contain on land(in a moist manner) to relieve the stress of trying to swim while bloated. Wait and see what it looks like before reintroducing to original set-up. If bloating prevails for more than a full day or so, I'd contact a vet. or an admin. on this forum for more technical and applied knowledge. I hope this helps, and keep us posted...
