I'd kind of like to redo some the aquascaping in my tank and possibly replace some of the rocks. Kind of like how 1/3rd of the tank ended up but never been hugely enamored with the centre or the right hand side. Not sure what I'd like to go with instead, just ... "something other than what's there now."
Kind of tempted to DIY a new calcium reactor and put that back on my tank. I'll stick with the 2-part dosing as the main level maintainer but a small reactor on the side could be fun.
Also kind of miss a kalk reactor for that matter. Got rid of my old one because supposely kalk is incompatible with zeovit but seeing as I've given up on zeo there's no reason not to try kalk again. Other than the nuisance of sourcing good quality kalk and cleaning the reactor periodically, it seemed to do a good job of helping maintain good levels AND help attack PO4.
I'd love to setup a frag tank inline with my system. Have all the hardward to pull it off .. just not the space or the time. With the basement reno nearing its end I might have the time ... so first step is reorg the tank room to make space for a frag tank.
A dedicated QT setup wouldn't hurt. I pass on buying new fish all the time now for fear of introducing something to the current inhabitants because I don't have a running QT. I once tried setting up a QT on demand, it was a total disaster, I'll never do it again. But having a running QT up all the time ready to take on a few fish here or there could open up some fun possibilities.
Dunno how much of this I'll actually tackle ... just some fun ideas at this point.