Well you are probably getting along okay for now but you are going to have problems eventually. You see, goldfish are cool water fish and prefer their water in the neighborhood of 72 degrees not higher. Bettas and the other fish you have listed are tropical fish and need to have a temperature of 78 to 80 degrees or they soon have diseases like ich, Velvet, fin rot or something of that nature if they do not develop one of the metabolic diseases having to do with the inability to digest their food properly due to decreased metabolic rates because they are cold blooded creatures and their metabolic rates are determined by their body temperatures.

The bettas usually do better with a pellet or natural food like bloodworms. A lot of the fish will eat bloodworms and your pleco will eat either the algae wafers or the food that the other fish do not eat but probably not do as well on the leftovers if that is all he is getting.

I am sorry to say that you REALLY need to seperate your tropicals from your goldfish and that the goldfish do not have nearly enough room in that tank. Goldies are generally high waste producers and need a lot of tank space. The first one is generally rated at 30 gallons and 10 gallons for each one thereafter. Bettas are generally very clean fish and will get sick leaving them in a tank of this size with large waste producers like this. You can keep a betta in a 5 gallon very easily but the rest of them are high maintenance fish.

Rose