What are you currently using for his litter?

I dunno, maybe the smell is because he’s not neutered yet??

I recently purchased one of the Litter Box Screen Kits from the BinkyBunny store, and I wish I had done it sooner. You clean out the poop on top of the screen, and you replaced the soiled litter underneath with clean stuff, and put the screen back on. I also put some hay on top of the screen. This has made a big difference, and I clean each litter box twice a week. It’s better to get a litterbox that’s a bit bigger, so your rabbit has room to forage for hay.

I use Lignetics wood stove pellets without accelerants, to absorb the pee. Any type of wood stove pellet without weird chemicals will work well.

I have 2 rabbits. I use Aspen Supreme pellets and I also sometimes use Oxbow Eco-Straw. Rabbits will usually pee and poop in one corner of the litter box and I think that it’s important to scoop out that wet area every day, and add extra litter if needed.

I scooped the wet areas and poops daily (left the litter that was still fine) and maybe once a week did a full clean of the litter box (removing all the litter and cleaning the box, the grid layer and the catch tray). I also used a wood pellet litter, it really is the best when it comes to odor absorption. The problems you are having with smell is probably largely because your buck isn’t neutered. The pee smell tends to be quite a bit stronger when this is the case. It could also depend on how frequently you’re cleaning out the tray.