Tanks with the intention to grow algae… Yup, algae, growing on purpose 🙂 The concept, grow macro algae somewhere you can control it. It also gives small organisms a spot to flourish. They are a natural food source for the aquarium. Some people use space in the sump for the purpose of refugiums. But to truly gain the benefit, a large tank is best.
To keep the thickness to a minimum, adding middle braces supports the tank from bowing outwards.
I hadn’t glued in the brace yet, so, a clamp helped keep the tank secured while I did the water testing. The top looks like it has something covering it. However, that is the pink foam reflecting on the surface of the water which is full to the top.
Same tank with the dividing brace finished. The open ovals allow water to pass through easily, while still supporting the tank.