I know Keith has been kickin butt with his setups and I have made my mind up so once I get my new lights to do this as well since I will have more space ontop of the tank. I plan to use plastic flower boxs, the type you put outside your window and use a powerhead like a Maxi-Jet 1200 per unit but my question is the layering of media. From what I have seen on Aro sites where this is a popular design is they have a TON of bio materials and is this due to the use of UV or the efficiency of bacteria. What are your recommendations ?

Here are some examples I found

And some more

Dan,
Those setups are awesome and should work very well.
Some of them look very neat with the media stacked in organized pattern.
W&D systems got their usage from the Chemical Engineering's material transfer columns.
Material transfer is basically a counter current flow of liquid and gases.
Liquid flows down and gases flow up.
Some systems use particular gas to strip particular material from the liquid phase while other systems use liquid to strip particular material from the gas phase.
Any way, the goal is to provide the largest surface area for the contact time.
The efficiency of this system is to prevent little channeling of water.
channeling means water flow does not cover the entire media, instead it finds areas such as the reactor wall or that it flows straight down the media in a linear fashion.
So to prevent channeling the media needs to be randomly packed so that water doesn't find a linear path.
What I'm saying is a nicely packed media does not work as well as a randomly packed media.
You know what I'm saying?

I compared the power usage and will be using Maxi-Jets 900. Got one on the way to test out :)

RH - random I can do :) Is there a ratio I should use for mechanical media vs bio? I was going to use a cheesy UV I got and want to use and think I need to add extra bio in the filter to make sure I don't kill the good with the bad.

I would only use the mechanical to trap solids and water distribution.
I think two layers would work. I have a firm and course plastic mesh pad about an inch and half thick and put a felt layer on top of that.
The felt will collect crap while the other will distribute the water.
Or you can just use an egg crate and put the felt on top of that.
My experience with a UV is that it is very good for green water algae and bacteria bloom.
As for its usage to eliminate the "nasties", in theory is good but I highly doubt that it can kill 100% of them and it only take 1 to harm your fish.
Fish are tough and I would think a great filtration to provide them with the best possible water is all needed to let their strong immune system fight off the "nasties" naturally.

I found some cut to fit air conditioner filters that they used bellow (green pad) and thought I would make an egg crate shelf with this pad on top of floss and under the crate lavarock and coral. Think that will work or should I invest in some other bio media? Trying to do this the most economical way.

Dan,
If you're going to use lava rocks, I suggest you check the price on pumice.
I believe pumice is more porous. Although is is bouyant in water, I think it might work for a WD system.
Thinking about it, I have not heard of anyone using pumice yet so you might do more research on this to see if there is any harm.

I like the way you think

http://www.skepticalaquarist.com/docs/aqua...ing/rocks.shtml

Pumice is aquarium-safe. In fact you may get some side benefits from using it: after it has been in place for six months or so, you may witness some slow decline in nitrate in the aquarium. This is due to de-nitrification carried on by certain bacteria, deep in recesses of lava rock, where the water is anoxic. If you pull out the rock and drain it, or worse, if you dry it, the de-nitrifying effect will be cancelled. So, treat matured lava rock as respectfully as you would a matured sponge filter. Its rather harsh and blank brick-red color is improved in time with some algal growths.

Nice filter. I wish I could build one that that will benefit all my tanks. The problem is they're all scattered around the house. I could have used my basement as my fishroom but the problem is during winter time. That place is a heater burner. It's cold down there.

damn i like the multiple side by side layers of the wet dry filter.

http://www.flowerhorncraze.com/index.php?a...ost&id=5745

Great discussion guys. Btw, i just order sheetload of bioglass as suggested by keith. Anything else i should add as even 24 litters cant fill out all the wet/drys im planning at. Should i mix them with pot scrubbers bioballs lava rock, anything else i should look for?

Here is a pic of the two mechanical media I'm talking about.
And that is how I layer them too; black on the bottom.
If you like, call Jehmco and show John this pic. That's where I got all my stuff.
Their 1" bioballs are pretty cool too.

Ken, becareful with the pot scrubbers. I think some of them say it is not aquarium safe on the package.

That's what I use matala sheets, very good stuff. Does not log and more bacteria surface. Do you know a good place for them? I need some more black and blue (more porous) sheets.

also tufa rock its very lite and cheap to buy at the landscaping supply