that link is overly complicated and probably requires you to go out and buy more expensive pieces and parts (ie powerhead which can run quite a bit- airpumps are much cheaper!)
so for all the folks who are interested im finally going to post my instructions here. maybe start my own thread about them so more folks will read it.
i am feeling particularly lazy so ive copied/pasted from a PM to someone who was interested. so ignore any info that doesnt pertain to the general population

the build will be the same
here goes:
if you have an established tank, use some media and MAKE your own filter. heres how to make one. ive given advice to a few members so ignore any info that doesnt pertain to you. any more questios feel FREE to ask!
here's how to make one. it is reallllly simple.
list of things you will need:
- an old fish food tub or any other container with a lid depending on the size of the tank to house it (like an old peanutbutter jar (plastic of course), big yogurt container, sour cream container, etc.,).
-something to poke holes in the plastic- a nail and hammer or a drill with a small. sized bit
-gravel or some other material to weight it down
-filter media (sponges work best)
-air pump
-airline tubing
now to build it:
-take the clean container and poke some holes in the bottom. like 8 or so (they should be no bigger than about a mm in diameter).
-poke a hole in the lid of the container that will accommodate the airtube and be just a BIT wider than the tubing(so the air can get out as it bubbles)
-take an amount of gravel and put it in the bottom (a small handful will be enough)
-put the airline tubing thru the hole in the lid and then run it in the container right down into the gravel
-pack the filter material nice and tight around the airline tubing. you can cut sponges to fit. just make sure its packed well. if not, the airbubbles will have lots of "options" to escape. the idea is to get it so that there is good suction thru the filter as the bubbles rise. if there is lots of airspace in there, the bubbles take the path of least resistance and suction will not be as good thru the media as it should be, and the filter will not work as well.
- put the lid on the container that now is weighted with gravel and packed with media.
-turn on the airpump and viola- nearly instant and cheap filter!!!
some troubleshooting advice:
-if it seems to float, add more gravel to weight it down
-test your water daily and do appropriate waterchanges until it cycles.
-if using mature media, ive found that they usually cycle within a week or so (or sometimes instantly if the bio load is low).
- if you dont notice reduction of ammonia within a week or two, try packing with more media...or if it was REALLY jam packed, maybe take a bit out.
these filters require VERY little maintenance. they are NOT mechanical filters (do not remove the solid waste in the tank) so they dont get all gunked up with waste. i have not touched my filter media in months!!!! although this means that with water changes, you will have to syphon out the solid waste- these filters do not do that for you. they just take care of the chemical filtration (turning ammonia into nitrites into nitrates). they do circulate water quite well tho.
good luck and feel FREE to ask if you need any further instruction or clarification. they truley are very very simple to make. once you make one, you might not buy a filter ever again. i know i wont smile.gif its a little extra work to clean the solid waste up, but if you regularly do partial water changes anyway, it is not a big deal as you should be syphoning up the poo anyway.
good luck and have fun making your filter!
i hope that gives some assistance to folks. my "door" is open if anyone needs help or advice. this is a fun rainy day kind of activity and a snap to do in an emergency (if your filter dies or you find yourself with a recuse fish and no filter handy)
cheers