Overflow without a hole in the aquarium are not a problem. Have me as on the page
Described an overflow of 32mm PVC pipe built. This I did not glued but wound with Teflon tape. The pipes are all tight and the big advantage is time they can still twist. But you should make sure that it all fits very tightly, otherwise the pipe system could solve.
In addition to the copies an overflow I have no glued an air hose in the first U-shaped part, this is flush with the inner wall of the pipe from (as is the to no turbulence and noise)
At this small hose I have connected a Defusor (Venturi). The Defusor is driven by the JBL 120.
Now the trick to the whole thing. The Defusor will suck air until the overflow is full with water and starts to tiles. So the system runs almost by itself.
To reduce the noise levels even further I have a Durso Standpipe-INSTALLING. (Coming up in the T-piece and is a tube with a cap incl. Hole and a small air hose)
The overflow is powered by an Eheim 1048 pump.
The whole system is totally silent you do not hear the quiet running of Pupem.
Tried more water to send us the 32 mm PVC pipe, which works well (tested myself) but then we the whole system much too loud and the beautiful aquarium can not be operated in the living room.
8 x Diskus
6 x Sterba's Corydoras
1 x Panda cory (unfortunately only one, but he is the grandpa in the basin - 8 years old)
25 x Red Neon
20 x Armano shrimp
Several Calendula Hand shrimp
Sera discus main feed
Tropical Discus Gran D-50
Tropical Discus Gran Wild
Tropical Krill Gran