Bottom feeder for 40gallon

[fishnatics]

With live plants, I would say nice school of cories is my vote.

 

[Deadliestviper7]

Red albino Kuli loaches

 

[Five 97]

Are you sure it is an ancistrus? They rarely get over 6 inches.

Are you sure it is an ancistrus? They rarely get over 6 inches.

There are others in the genus ancistrus, such as the trinidad (common) which can grow to over 2ft. the one you're referring to is the BN.

yo-yo loaches get big and are active fish, I wouldn't keep them long-term in a 36" long tank.

cories would be a good idea, but goldfish aren't tropical, they need cooler water than most tropicals.