That was part of the main draw to the surf for me when I first bought it. It is impossible to leak. If it was to get backed up or anything it just overflows into the sump.
I’ve neglected the surf for weeks and when I opened it, it was just packed with algae and the top layer was white from being too close to the leds. Scooped out a big handful and it was back in business
I’ve also had my air pump die twice. This is unique for the surf because it does not use a water pump. The air pump provides the flow and oxygen. And both times my air pump died I didn’t realize it…the algae stays submerged. The lights remain working. It just doesn’t filter water as their is no flow. However my algae colony remained healthy and I didn’t need to start over.
If the pump died on a screen one all that algae would dry out and die