In need of FW tank advice

[RhinoWiz]

Hi. My name is Joe and I have been maintaining a tank for 3-4 years. It started at 10 gallons but quickly grew to 40. The tank is 18"L x 36"W x 16"H and it looks like they have plenty of space, but as my fish are getting a bit older some of them are beginning to look a bit weathered. They have a few different little spats they get into (a couple like to chase each other around, a smaller one likes to pop out of places and scare some of the bigger ones, ect.) but I'm not sure where the line is or if any of that behavior is ok. I definitely don't feel like there is any bullying/attacking that is as bad as I've heard to look out for, but then again, I'm the amateur. Any advice would be wonderful. Thank you.

 

[brennae]

What kind of livestock do you have?

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