I have a seaclone that I modified into an in-sump skimmer. The black part you see is called the Mazzei injector. I used the 3/4"(you can find it on the internet or the big auction site for about 35-40 bucks). Also you will need a 600-800gph pump to make this work. I have mine setup as a downdraft to have more air/water contact time. anyway, it works great, my cup fills up every few days will good gunk. All in all, i spent:
$100 bucks on the seaclone that didn't work
$35 on a 600-800gph pump
$35 on the mazzei injector
$15 bucks on misc
total $175
If I had known better, I would have saved all that money to buy a quality skimmer instead of shorting myself with the sucky Seaclone skimmer.
hope it helps