Hey everybody! New user with design questions

[arinco3]

By sealed I mean so that water does not leak out where it shouldn't, sorry about that.
There does need to be enough airflow in between the falls to oxygenate the roots if I remember correctly.
The rafts will be removed. We have thought of using hinges for a door-like mechanism, but the isle space is too limited (40 inches).
So I proposed to use a pin locking mechanism to simply hold the boards in their place to slide in and out, similar to some windows.
See attached sketch.

Thanks!

Alberto