You could try to prevent them. :lol: Where did you get this design concept from? The inaccessible areas I mean. Have you been looking at the designs people have been using for this type of tank? This is a pretty big project and I hope it works for you too, but I think you are looking at a nitrate factory with your current design.

Only issues I see with leaving that space accessible is it resembles a invert trap, craps, snails and shrimp may not find their way out after getting in. It also maybe a dead spot for flow and lacks proper access for cleaning which could become a source for issues down the road, ie livestock could die in there or nuisance algae could bloom from there.

Love the idea though, but personally also think your stand it too high for this style of tank.

The top lid is removable. Not siliconed in so I can clean it if I have to.

350 gallon per hour pump on one side to keep water flowing through there.

Crabs will live in it. Not concerned with algae growing in there.

Been researching it for months.

No one else has tried this like this.

If it doesn't work out I can cut the baffles out and remove the shelf if I have to. Been talking to lots of tank builders who say the key to it's success is flow and a large clean up crew.

Holes are only big enough for chromis, damsels, crabs, and shrimp. None of my tangs will get through the hole once the O-ring is in place.

350 gallon per hour pump is nothing. To have enough water movement in there you'll need like 750 gallons per hour in each of those chambers

I don't want it to be too powerful to keep crabs and fish from entering it.

The enclosed area is 3.5' long x 2' wide by 15" high.

It would suck to see you do all this work and have to take it apart in a month or 2

You should set up a closed loop in the baffles. Draw water from the first section and have it come out in the last section

Yes it would lol.

But there are a lot of people who have worse flowing sumps than this design.

You never know till you try. It's going to be a work in progress. Lots of tweaking along the way.

You could always try to make some sort of crab ladders (egg crate?) so stuff can climb up and out if needed.

Good idea. I'll do that.