I stand by my statements, it was a cyano farm and every time I rinsed it the water was brown with detritus - nutrient trap. every time I cleaned it it would grow back nicely but there would still be cyano on the screen. cyano isn't totally bad, it does take up nitrates too, but i wouldn't want to encourage its growth.
can I clarify anything else?
If the screen grew cyanobacteria, then there was something wrong with the growth on the screen. It does not grow on properly functioning screens.
Yes, filamentous algae traps detritus in any setting--that is part of its nutrient procurement. However, "nutrient trap" is not necessarily applicable in the same sense in other cases, like sponges, etc. Any breakdown is being utilized or consumed extremely quickly. It does not have a net effect on overall water quality if everything is functioning and is removed during cleanings. Again, I believe there were some initial misunderstandings.
Now, to clear myself up a bit. I started using scrubbers just over 8 months ago. By no means do I believe they are the miracle "cure-all" and I won't defend them as such. In fact, if someone simply says they don't like them, don't want to bother with the maintenance, don't like the smell when cleaning them, don't like the extra lighting/energy requirements, don't have room, etc., that is fine and I leave it at that. But when broad statements are made that unnecessarily detract from scrubbers and their use, it is necessary to clarify them. I held the exact same views that you do now just months back, without even using one. I knew of the sediment trapping properties of filamentous algae, as well as various phytocompounds that are released. After having one long enough and seeing what they are capable of, most of the reasons out there for not having one simply aren't valid (or were the result of a mistake somewhere, either in design or maintenance).
All that said, these are our individual experiences and, to some degree, our own opinions. I don't feel I was beating a dead horse at any point in time, since I didn't necessarily agree with your initial statements to begin with. I simply probed into the situation to see what went wrong and where, since that is not how scrubbers are supposed to work. At no point in time did I question your own experience with scrubbers or anything of the sort, but your experience does not necessarily qualify your initial, rather sweeping, statement, nor does it reflect the usual experience with newer scrubber designs. I was simply trying to explain that in a more subtle manner for anyone else reading the thread.
You may or may not be interested at this point, but here is my scrubber thread, which describes my setup and how I went about doing everything from design to maintenance (and even nutrient limitation and the odd results that show up when it occurs):
http://www.aquariacentral.com/forums/showthread.php?t=217178 The design was quick and junky, but the basic requirements were met and it is/was a success.
