Back when I set up my 720 liter tank, I gradually came up with a DIY filter, based on sewage piles filled with filter materials. It worked really well, and although it had kind of a Super Mario feel to it, it didn't look quite as good as I'd like it to. I decided therefore, to take the experience I had from that, and built something that worked as well, but also looked good (or at least better). This is the original setup, with sewage pipes, stacked onto clay bricks:
As the tank is currently empty, while I am treating the fish for flukes in a smaller tank (a half filled 530L/140gal), I decided to plan this out a but better, and also take pictures while I was making it. I am not at all very handy, but it seems to be getting along pretty well. I must have spend more time making this video/illustration/render, than I have spend making the actual filter..
As explained, I am not very handy, so in order to mount the acrylic plates (ordered precut to measure) I had to freestyle a template using some bricks, wood and a little bit of paper.. If it works it works. Silicone dries fairly fast so I was able to complete this within a couple of hours. I am building two of these, and each will have two power heads that move 1000L/hour.
At the moment, I am waiting for the silicone to dry completely and for my order with filter mats and ceramic filter media (and filter bags) to arrive. I am also very excited to try out a phosphate remover that I ordered, as I was having issues with black beard algae and brown algae from too much silicate in our tap water.