CichlidFish.com - Fish That Think.

  I Have a Pleco in a 50 gallon tank with 3 large Fancy gold fish.  The tank is heated, filtered, has air, and the parameters are normal.  He is about 6" long now, and swims around for most of the day like a normal fish does.  I have never seen one do that, I was just wondering if anybody else has. 

Do you feed Him?? I mean nightly you need to feed him some algae waffers.. Do so when you turn the light off or the golds wil eat them.. Also goldfish dont' like warm water.. So keep the heater at 74F OR off.. Just make sure it does not go below 72F so the pleco will go dormate OR death at 65F.. As it is summer time, I turn all my heaters off.. most tanks maintain a good temp of 76F for long periods UNLESS you keep the room at 72F.. then a heater is needed..

YES he will swim if the pH is to high or a ammonia problem or he is HUNGRY.. they wil swim looking for food at the top..

Mine is always out in the day and is more then well feed, He would hide all day and not come out tillnight till about 5 inches then he just stopped caring and is out and about all the time now (12 1\2 inch now).  Also your lights might have something to due with it, Well I had my plants and lights in my tank all my plecs would hide but after getting ride of the plants and redusing the lights to keep algae in check even my small 3 inch plec would come out all the time day or night.  But keep in eye on the food intake to be sure he is well feed and make sure he has spots to comfortably hide without needing to bend in half to fit and if he still comes out just be happy to acutely see him.

My PH is quite high, 8+, the ammonia is 0. I know what you mean about them going to the top for food, in one of my other tanks I have a pleco that is 10" and loves  to eat regular fish food, he evan lets me hand feed him.  The temp is definately cooler than normal, and I have noticed a difference in the Golds behavior when it is warm.