This is, and has been, my set up for a while. When you are not quarantining, keep the sponge filter in another tank, to keep it cycled (or add a pinch of food once a week to the qt tank). It only takes one time to not qt fish and you'll be sorry! A little more than 2 years ago, I added a swordtail directly to a community (the last fish in a 55 gal) because I 'ran out' of qt space and lost 25 black neons, an sae, and half of my corys to columnaris, and the meds to save my angelfish and the rest destroyed my plants. Not alot monetarily, but still devastating. Especially if you're stocking expensive fish like discus, its worth a small investment!