Hey Thunder. If you're not running a sump, I think what you have there is about as good as any "hang on the back" types. I was running one of the older ones (not dual) on a 55 gallon tank and it worked. For me it was a pain to keep the preskimmer at the right level in the tank. It has to be a certain distance below the water level. If you're not running a sump with overflows, the water level changes constantly due to evaporation. Of course, if you are really consistent with your top off and keeping the water level constant in the tank, you will have pretty good results I think.

All that said, if you can run a sump there are some cheap in-sump type skimmers that you can get for that size tank that are a little easier to use I think. There are also other benefits to utilizing a sump (better yet a sump/refugium combo) but that's another conversation .

Oh yeah, one more thing. If you're using a bunch of live rock and maybe some live sand for biological filtration, I would remove the blue bio-bale stuff.

Oops, I lied, one more thing. There is a small wedge shaped sponge that comes with the unit. It is supposed to be placed into the return line going from the unit back into the tank and it's purpose is to limit any microbubbles from sneaking into the tank. This sponge- like any sponge- can easily get clogged up with gunk over time. Do you see where I'm going with this? If/when it does get clogged with gunk, the water can't get through the line back into the tank from the box efficiently. Thus water can "back up" into the overflow box and cause a flood. This is a major concern. There are 3 ways to correct this. 1) Constantly clean out that sponge! This is the best if you can guarantee you'll do it literally every week. 2) Remove the sponge. You run the risk of some microbubbles in your tank which really bothers some people, but you eliminate that flood risk. 3) If you have enough room behind your tank put together some sort of emergency flood spillover bucket/barrel that would catch this water in the case of an emergency. It doesn't have to be able to hold all 50 gallons of your tank, just has to hold enough in the case that it emptied down to the water level at the intake to the CPR skimmer box. If you've used it you'll know what I mean, but it's hard for me to explain it in writing. Please note, having the new dual system may eliminate a flood risk if there are two lines going back into the tank. I haven't seen that dual one, mine wasn't the dual, so I don't know if that's how it works. If there is still just one line going back in, though, then the flood risk is still there with that sponge.