I glued the pvc
with a normal pvc
glue, and used 100% acetone to clean the connections. After the glue dried, I flushed it with tap water a few hours every day for a week to get the glue odor out. Then I let it sit in the open air for a few days while my pump arrived. When it finally did, I ran it fill of water and activated carbon. After this there was not a slightest hint of smell from the glue.
As far as the short and tall sections. The short section does course to medium mechanical filtration. (depends how tight I wrap the filter media around the 3/4 pipe. I have a picture of this piece in the op). This then goes though the pipe at the bottom into the taller section. In the taller section.
In the taller section. The water is going to pass though some quilt batting, then though a 30 micron house hold water filter that you can pick up at almost any hardware store. (I want to use a larger size micron filter, but having a hard time finding any). The way I have the micron filter in place is hard to explain, I'll have pictures and a video to show how I built it. But after the micron filter, the water then passes though some activated carbon. (temporally there for now, after the filter is "broke in" I'll stop using it). Then finally though some bio media before reaching the pump to be pumped back into the tank.