This is very true. I've said in other threads. Did you ever notice the Eheims have much less GPH for the same size tank recommendation as say Fluval and other manufacturers. It's because they believe in the effectiveness of bio-filtration not the speed of it. The 10X turnover thing is from the fish only tanks where you need to remove large waste.
72G - 1 Eheim 2215 - Effective turnover less than 2x
- No Powerheads
46G - 1 Eheim 2213 - Effective turnover less than 2x - No Powerheads
Is if I were to use two eheim 2215's which would put me at a 5x turn over rate per hour I could have this stick in my tank?
Thanks for all the replies, more are welcome.