converting to goldfish

Question
I have a 35 gallon tank that has been set up for a year. In the beginning i cleaned everything too much and lost almost all my fish. I've been leaving things alone lately and the 3 small fish that lived through the last 4 months seem fine. I recently cleaned a bit ( i don't think too much)and am interested in changing to a hardy variety of goldfish. The only thing is I'd like to keep pleco with them for a cleaner tank. Can i safely keep plecos with goldfish and can I just start adding goldfish to my existing set up? I'll unplug the heater of course! Thanks in advance! Maria.

Answer
Hi Maria;

If your house temperature drops below 72f at any time your plecostomus may not do very well if you unplug the heater. Once you unplug the heater your tank water temperature will drop or rise when your room temperature does. Goldfish prefer their water to be below 72f so it's okay for them in the cooler months. If your house is at least that high all the time, it would be okay for the pleco. You just don't want it higher than 75f for long periods. Goldfish just don't like it. It can be a tricky balance. That's why it's recommended not to mix coldwater fish with any tropicals.

Keep in mind that a 35 gallon tank with a plecostomus can only have two goldfish with him, and no other fish. Plecos get VERY large (a foot long) and so do goldfish (6 to 8 inches or more). They are all also pretty messy guys too. Be sure to keep up with weekly 25% changes along with gravel vacuuming. These weekly partial changes are very important. Larger changes less frequently are what stresses fish and harms the biological balance.

You didn't mention what types the little ones are. It could be very important in your decision on keeping goldfish. If the little guys are tropical, they will need the heater too. Some fish like to pick on goldfish, or could be eaten by the goldfish. They are also an extra bio-load on the system and may possibly too much for it once you add the goldfish. It depends on how big they get, how messy, etc. Let me know what they are and we can go from there.   

At Your Service;
Chris Robbins