I have an classic 2211 for a 30 gal
and the Ecco 2271 for a 40 gallon (its rated 60) and absolutely love the Ecco over the classic.
On the Ecco, the instructions said to use only half of their biomedia if you wanted to use a substitute.
The Ecco keeps the water in pristine condition.
If you give it a chance, I'd bet you'll like it a lot.
My little 2211 is very good, but the Ecco is great, in my opinion.
Is this for your 20 high?