More information of DragonFlow:
DragonFlow gives user the freedom to either install the DragonFlow kit for saltwater setup (for use with sump filter) and achieve better water quality, or to remove the DragonFlow pipe set and seal the hole with the threaded cap in exchange of maximum in-tank space. Shown below is the diagram.
1). Cut tank-bottom foam open. (Do not remove the foam attached to tank bottom, only cut small area enough for the plumbing connection.)
2). Set female bulkhead assembly through the tank hole, place a rubber gasket ring between the glass and bulkhead.
3). Place the 2nd rubber gasket ring between the glass and bulkhead and screw tight the male bulkhead assembly into the female bulkhead from underneath. Use tyflon tape or plumbing sealant if needed (do not use PVC glue as you may need to undo in the future).
4). Insert the return pipe (the thinnest pipe) into the assemble where it fits, then insert the inner drain pipe (the 2nd largest pipe) onto the bulkhead where it fits;
5). Insert the outer drain pipe (the largest pipe) onto the bulkhead where it fits.
6). Set up the return outlet, either for one outlet, or with a T that directs flow to more than one outlets from tank top or under tank top.
This bottom screen is designed to in-take wastes from water near tank bottom, and can be flipped upside down: In the position shown above, you have deeper sands; If you have no sand or less sands, you can flip it so it can in-take wastes from water closer to the bottom.
This is how it looks underneath the tank inside the stand. Feel free to use the reducer and elbow anyway that suits your needs.