I will have one pleco in a 20 gallon long tank...?

In my experience plecos are very docile. Ive had my plecos with some very aggressive fish and neither have bothered each other. In Fact the fish dont even know hes there. It depends what kind of pleco you have. Some of the rarer plecos can't be kept with other plecos. But they should all be ok with any fish you choose. As its a 20gal maybe a few smallish angels would look nice. They shouldnt bother your pleco. Hope this helps

nicely-known may well be best for those fish. pay attention although, your Gourami's and Pleco will quickly grow to be too great for that tank, as Pleco's % fifty 5 gallons minimum, through their great length.

It depends what kind of plecostomus, there are some tha grow a lot. Some others grow less. Live the gold fishes, they go together well. No need to have two plecos, One is enough for an small tank. You better get firs a bigger tanks and then get more fishes. Good luck.

In my experience they only appear to be docile at the bottom of the tank. I picked up a tiny chocolate pleco along with a female betta, anglefish and some zebra's. One by one they all ended up with torn, then shredded then missing fins. I presumed it was the female betta, but I never caught any action. Finally up late one night, I witnessed "Pleco Playtime"! He looked more like a hungry shark in there instead of a sleeping lump. All the others died. I tried a few more fish after that, with the same results. Sxnofabixch, (SOB) as we named him because he really put up a fight in the bag on the way home as a baby, ruled his 10 gallon tank alone until he reached about 10 inches long and had trouble hanging on the side of the tank without sticking out of the water. I moved him into a 20 gallon after that, and added a jack dempsy. SOB didn't like JDaniels and tried to get him, but never could. Jdaniels teased and tormented SOB, and SOB gave as good as he got. They got along fine, bickering and chasing each other around, until 5 years later SOB simply lay down and died at about 16 inches. That Jdaniels was just tough and smart enough to equal SOB, and turned out to be a very playful engaging fish, playing with pingpong balls in the tank and jumping out of the water for food. The site below notes pleco's don't make good companion fish though, and with few exceptions I'd have to agree.

http://en.wikipedia.org/wiki/Plecostomus

Before jumping into angels, keep in mind they can grow nearly as tall as your tank, so 'long' style aquariums aren't really suitable for them. Still, you can keep one for a while.

The larger portion of Plecos grow extremely large, so it would help if you mentioned what type. If it's a common one they grow well over a foot long. While plecs tend to be docile to other fish, they can be extremely territorial against their own kind, so be careful and research the one you have before adding any more.

Almost any fish suitable to a 20 gallon tank can be kept with a pleco, so really you've narrowed it down to hundreds of species and its really hard to recommend any one since we all have different preferences.

doubt Ralph really cares what you keep in the tank with him - Plecos spend most of their times on the walls of the tank lol

must be looking at themselves in the reflection lol

Maybe a Bristlenose Catfish, they are similar to pleco's but smaller. Or some other catfish. Thats what i keep at home with my baby.