That is interesting. IIRC, that is what I followed to build mine (only built one to try it). Although I remember using a hole saw to rough up the screen. Now when you say hard to make it work right, isn't 'working right' growing algae? A continual cycle of 'grow and clean" so to speak. I had placed mine in my AC tank, with the least plants. It grew algae for sure, completely filling the scrubber before cleanings. But what I found happening was the algae was spreading outside of the scrubber to plants, decor and such. (I think due to the spreading that was happening as I cleaned it up maybe?).
Once I took it all out, no more algae anywhere, even thought I read nitrates very low. Perhaps the few plants I have are just enough to keep the nitrates in check. One thing I remember is there is not alot of info on this type of thing. I do remember seeing alot of pictures in sumps, which is probably what you are indicating works so good. I guess in the end, no more for my freshwater tanks, I don't have any algae in any of them.