[kkoch]

I have a pleco that has been in the tank a few years. After additions of some corys and more plants, he is becoming increasingly aggressive to all inhabitants that venture in his lower half of the tank. What could be the causes?

 

[mitchfish9]

Is it the common pleco that you have in your 30g in your sig? Because maybe he is just getting to the size where he needs more space than a 30g and that is making him uncomfortable.

 

[kkoch]

Yes it is.

 

[mitchfish9]

How big is he? I would not keep him in there unfortunately. He will just get too big

 

[kkoch]

He's approx. 4.5 to 5", but has been that size for over year and a half.

 

[n00dl3]

Sounds like it is a young male. Male plecos are very territorial. If you want him to be less territorial, you'll need to provide plenty of hiding places for him.

 

[kkoch]

I think my son and I are going to swap plecos. He has a small in a 35g with cichlids. My bigger pleco will have more room.

 

[Diana]

Common Plecos can reach a foot to two feet long. There are several species sold as Commons. I would not keep one in a tank under 6' long.

Return the Common to the store and get a fish more appropriate to your tank size.