The affected guppy is housed with five other guppies, four neon tetras, six Amano shrimp, one female betta, and a single cory in a 14 gallon tank running an AquaClear 30 with two sponges and two biomax. It is a decently-planted tank containing hornwort, guppy grass, Amazon sword, aponogeton, onion, and dwarf lilies, but none of these were added recently. pH is 7.6, ammonia at 0, nitrite 0, and nitrate 5 ppm. Temp is at 75 degrees Fahrenheit. I did a 25% water change yesterday, and all tank inhabitants, including the affected guppy, were acting fine both before and after the water change. I don't believe I inadvertently introduced any harmful chemicals to the tank while changing the water. All tank inhabitants get along fine. I only noticed that the guppy was prolapsed when I woke up this morning. She was hanging at the surface and acted in a lethargic manner, so I isolated her in a breeder box (but in the same tank). As the day progressed, more of the pink tube trailed out of her anus. She is now gasping and follows a cycle of motionlessly sinking to the bottom of the box then swimming back up to the surface of the water. She doesn't look too good.
