I haven't been able to open your photo, but a UG is pretty simple.

The uplift tubes are used to force air down, which pulls debris in the substrate down, below the plate, which is both a blessing and a curse, because while it will force plant roots down and encourage growth, it also traps debris below the plate to create a massive tank disaster waiting to happen, and why any tank with a UG needs to be heavily planted and regularly siphoned out through the uplift tubes, to draw out all excess mulm.

If you are going to use an UG, don't even think about it without a reverse powerhead, or an air pump so powerful, it will blow away a tank 3 X the size you are setting up.

Yes its very simple. Put in uplifts and cut to size if needed, cap unsused lift tube holes before adding gravel. Put in an airline with defuser from pump down the tube to the bottom and connect to airpump. If pump is below waterlevel a backflow check valve is mandatory. The bubbles leave defuser, flow up the lift tube drawing water from the tank through the gravel and up the lift tube. Remember the tank will cycle so test the water. I have to disagree with bird i've used ug filters for 40 years, they work if maintaned well.

james: I agree. UGs work- IF maintaned well, and that's the problem. Too many people see clear water and think all is well, when it isn't.

The only way operate a UG effectively is with either a reverse flow powerhead, or a truly brodacious air pump that will create as much downward push as a powerhead, then maintain it with regular water changes, siphoning out through the uplift tubes, and too many don't, creating conditions for sudden die offs when gas bubbles trapped below the plates finally erupt and the tank becomes a death trap.

It happens suddenly: The hapless fish keeper goes to give a morning feed to what they thought had been a healthy tank the night before and finds it full of dead fish.

Hi
Here's my two cents lol Something often not mentioned on these is gravel size and depth. Too fine and it will block very quickly too corse and it's not effective. IMO 2/3 MM is just right. And since water always follows the path of least resistance the gravel must be the same depth over the entire area otherwise your only using a small portion of the material.
Also it depends on what you want to keep. Big messy fish
will defeat the system rather quickly. They are also long term nitrate factories lol. While nitrate is not nearly as toxic as other things long term it will cause problems.
There is no such thing as a "perfect" filter system so regular water changes are necessary no matter what you use.
Though rather ugly a simple sponge filter works just as well as any other. The only really important thing is the nitrogen cycle
For a first tank UG is okay but keep in mind that nothing will work perfectly. gary