Chree, I don't use a backpack overflow, I have a 25 gal sump, my whole setup is organic and backpacks are more for chem treatments and seperating the 2 enviroments.
Sol, my 100 gal freshwater has been up for close to 10 years so I couldn't say the exact amount of cycle time.
I was just getting started back then.
In my reef I have yellow tangs, 2 clowns, damsils, about 30 anaenomes and lots of corals.
and I don't buy my water I make it myself, you can never be sure with that store bought shit.