Fish acting strange

Question
The pump on my 25 gallon tank stopped working.  I have five large gold fish (four to six inches long).  The sucker fish died within six hours, but I fixed the pump at 16 hours later.  While I was in the tank I vacuumed the bottom and changed about 1/3 of the water.  Now five hours later, the fish look like they are sucking air and won't stop.  Any reason why?  

Answer
Brandon,

Your fish are letting you know the tank is not big enough. You need a 20 gallon minimum of water each. If you have 5 six inch fish they need to be housed in nothing smaller than 100 gallons. Goldfish are the most wasteful of fish and the water turns to ammonia very quickly. Another problem is your goldfish are cold water fish where the pleco is a tropical fish. They should not be housed in the same tank. When cleaning the gravel never go to the bottom. Always leave about 1 inch of gravel, at the bottom, alone. That is where the good bacteria is living. Sounds to me like the tank is setting up again, meaning recycling. I would add an air stone to the tank. From your description sounds like they are lacking oxygen. The air stone will put the much need oxygen back into the water. Give that a try and if they don't get better or get worse in the next day let me know. Test the water for ammonia every day and according to the results do a 25% water change daily until the ammonia is gone.