I received Montey, aka my money tree, as a gift from my mom a few years back. It looked horrible when I first got it; three out of the four original trunks it had died out from root rot, but I've managed to keep the last one going after repotting it.

The leaves on my tree are a lime-green color (as shown above) and are browner at the tips. They're curling up as well, as you can see from my pictures. These leaves have also gotten considerably smaller, and I've noticed the new growths are a lime green instead of a healthy, dark green

I planted the tree in Miricle Grow cactus mix, added small river rocks (it's a fine rock mix, think very fine gravel) to the mix to increase the draining properties, and only water the tree when the soil is dry. I spray the leaves to add humidity to them, since my house can get dry, and set it outside in the shade when I can so it can get the humidity it needs when possible. What am I doing wrong? If anyone could give me tips, I would really appreciate it!