Erratic Behavior - Please Help?

[MadameFizzgig]

I have a violet Goby who is typically very calm and usually hangs out on the bottom of the tank. However, lately he's been swimming back and forth across the tank, going to the bottom and then coming back up in a circular pattern.
 
I've added prime to the water, and stress guard, and his SG is normal. I also did a partial water change, just in case. I did get a new filter recently because mine died, but I put the old filter cartridge in the new filter, so it shouldn't be that my tank would need to cycle again.
 
He's the only fish I have in the tank, so I'm not sure where he could have gotten an illness because no new fish have been introduced. What should I do?

 

[Baccus]

If the violet goby is like most other goby's then I suspect it doesn't have a complete swim bladder like other fish that help with buoyancy. But he would still probably be reactive to barometric pressure changes, in much the same way of Khuli loaches, and most catfish. Could you be expecting or experiencing a significant weather event?
 
Is the goby in full fresh water? Apparently they can survive for short times in pure fresh but for ultimate health need brackish.
 
Some more tank information will help us, could you please provide the following?
 
Tank Size and water volume
 
Tank substrate - sand or gravel?
 
Tank Temperature
 
What are you feeding it

 

[MadameFizzgig]

Problem resolved itself, thanks anyway. Dini is doing good, I guess it just took a couple days for the water to be up to his standards.