You are
RIGHT on my slip up on the anaerobic.
You are WRONG on the fact that there are no anaerobic areas in an UGF.
In an UGF, the water does not migrate throughout the bed in equal flow and in fact, the water flows through only a portion of the bed, with the remaining areas being dead areas like in a sand bed.
It works like a plenum only it has areas of more flow
Now, if there is only a thin layer of substrate over the plate, there would be no anaerobic area, but if there wasn't enough live rock to handle the nitrates, then water changes can control the nitrate problem if one develops.
Back in 94, our club set up an experiment with water and dye. At the time, it was solely to point out differences between UGF and pre-filtered reverse flow UGF.
What it also ended up pointing out, was that the crushed coral we used for substrate was stained through out the the depth in many areas, but in other areas, only the top surface granules were dyed, with the crushed coral below still it's original colour, and the bottom layer in contact with the dyed water under the plate, also stained.
The RFUGF used power heads only for this experiment, but the normal UGF used two plates with the left side utilizing air for the uplift tube and a Hagen 201 power head for the right hand plate.
The reverse flow substrate exhibited similar dye patterns to the normal UGF.
We left the set ups running for about 6 months.
Try just the normal UGF set up and put dye in the water and see for yourself.
You have to replace dye occasionally as the water seems to clear itself after a period, probably because of the dye being absorbed by the crushed coral.
At the end, syphon off the coloured water via a tube down the up lift tube, and then "core" sample the subtrate in numerous places around the sand bed.
We used a soil core sampler at the time, and it was about 1/2" in diameter.
I find it very disturbing that you would hand out this kind of information if you do not truely understand what anaerobic areas are or what they do. This is the type of thing that leads people to have problems with their tanks. I agree that CC and UGF's USE to be the norm, BUT there is good and solid reason that they are not the norm NOW, that is because they both cause PROBLEMS!!!!
If you find it disturbing, it's because you haven't enough experience with the salt water use of UGF. You're welcome to visit and see a 40g set up that hasn't had a substrate change in seven years, and, it has NO nitrate problem and little live rock in it. It is one of my prop tanks. (if you are really up on things you must have already read that it is a great probability that the way the nitrification process works, is entirely different than the way we presently believe it works)
In the years I've been in this hobby, I have set up and used pretty well most of the methods that have come along. Most of my ten systems are presently run as bare bottom Berlin method, with one shallow sand bed and the before mentioned UGF. The use of the BB Berlin is purely a personal preference.
I have used UGF, plenums, shallow sand beds, deep sand beds, and hybrids of these, and all methods work. These methods didn't die out because they didn't work, they became less dominant because people wanted to try new things that come about. Do a poll post on RC and see how many are STILL using these older sytems successfully today. I have no doubts that new methods will still come about, but that won't mean that the systems in use now, don't work.
Germanman: There was no trial and error with my set ups in any of the methods I chose over the years as all methods work.
.even though u had several die offs..
If you read thoroughly, the die offs were on Berlin method tanks and were due to elevated temperatures when I was on holidays. They happened three years in a row, the third and worst being a month after I installed a new furnace with whole house A/C to prevent losses like my two previous years, only to leave on holidays and have it fail.
THE ONLY TANK I NEVER SUFFERED ONE LOSS IN WAS THE UGF TANK.
However, the fact it was UGF never figured in not loosing anything, it was more the location of the tank where it remained cooler than any of the others.
If you are concerned about simple methods for new hobbyists then the bare bottom Berlin is as simple as they come and, it works extremely well, but I don't see you recommending that.
UGF, plenums, sand beds shallow or deep, are all systems that work and NONE of them are complex.
People make a system complex when they don't read all about a method before they get into it. They also tend to take short cuts or rush through a process rather than proceed as designed or intended.
Its unfortunate that in this hobby, when something fails, the blame is many times misplaced, with the resulting errant facts being passed on especially since the advent of this computer age.
Simple examples are "my fish got ate by my anemone", or, "my fish got sucked into the intake". While it does happen occasionally, MOST of these scenarios involved fish that died of some cause, and ended up being found in these situations.
The same applies to filtration methods. If something doesn't go right, then blame the set up.
If a lot of people have success with something, and some don't, that doesn't make the "something" necessarily at fault.
