Back in the day it was always penquins
You know, you are right. I used the Penguin a few years back and thought of them when I got into Saltwater. I bought two of them and they are great for pushing water but they really are not good for attaching to the tank...Verrry Shottty.
I am going to needlessly replace them with the maxi-jets now, because I like the way they attach to the tank,,,I also keep hearing how good they are..and for $20 to replace what I paid $40 for, not too bad I must say...