Bulkheads/return pump question...

[IE Reefer]

Hello, I have a 29g DT that’s been running for almost a year and I want to upgrade my return pump by installing a bulkhead and adding a return jet, would that be a possibility without removing everything from the aquarium and using a small tarp to cover the inhabitants from debris? I would also like to add black paint to the back of the aquarium due to not having a background, could I do that without killing anything?

 

[Boostable]

I wouldn’t advise either of those on a running system. However if your going to roll on the paint that could be done.