Hi,
in 870gal with nearly 10feet length i use 2 of them opposite each other
(there is a jumper in the controller to change for that operation).
As you might know there is a certan resonance? wave-frequenz for each tank-length
to operate at (and to find with the poti on the controller) to have the max. highth of waves.
In smaller tanks (i.e. not as long) i consider these frequence as too high (fast) to give a natural
look (too fast, too many waves). In my 10 feet its about one wave every 1-2 seconds
which i like.
I think it pays to have a overflow, where the water does not fall a long way to the button,
else you will have the wave sound, which is not bad but loud in your room ;-).
Tunze themself state, that they would recommend other water movement also to move
the water through the tank and not just forward and back.
I love esp. the polyps of my catalaphyllia in the waves
.
best,
Ralf