Scrap, I hope I helped you out, that is cool if I did. One other thing I would recommend that your sump not sit directly on your hardwood floor.
Kevin. So your sump will be behind your DT. Will it be at a lowever level than your tank? I am just thinking about the gravity flow of your overflow from your tank to your sump.
Yes they do sell PVC that scr ews together. But these connectors are actually more prone to leaking. You have to use teflon tape, the threads have to be tightened down enough, then if there is any stress on your pipes the threaded connectors are physically weaker than the glued connectors. There is a type of connector that you could use called a union. Google PVC union and check them out.
The gluing of the fittings is easy, when you get used to it. Clean the inside of the fitting with the primer, the outside of the piw with the primer. Smear the glue on the same places and slip the pipe inside the fittings. Give both a twist to to make sure the glues is all over and then let it sit for an hour or more and you will have a waterproof connection.
As far as what goes in your sump, that can be as varied as what goes in your tank. I personally have some LR, some cheato, some LS, my skimmer, heater and sometimes a HOB filter. Others may have other equipment and baffles like ameno was talking about. You do not want bioballs in your sump, those go in a wetdry filter which is a different type of filtration.
