Hi bro MbmC,
I saw SantaMonica's scrubber & actually asked him about his design of having 2 outlets(1 positioned lower, & the 2nd one higher on the enclosure). Seems like the thick algae growth would easily block the lower outlet. As the water level rise in the scrubber chamber, the higher outlet comes into play to provide the additional drainage to avoid an overflow. If a bigger outlet is not possible for your design, you can consider having a 2nd outlet. It's an insurance against lighting short circuit.