very tidy looking job but this does not circulate the water properly and water spashing in on top does little for the water on the bottom and overall water quality.
Actually the fresh water entering the tank is the first to exit. ! Whilst it may be ok for yakkas, with a good load of slimies I.think would struggle..
The real test will be how long it takes to clear out a few squid squirts...
Perhaps u can add something inside to direct the water to the bottom.