OK heres the scoop. it means "stand on back" I know what you were thinking. I have an aquaclear 300 running my 125 alone, its just not enough for the fish load I have. I dont want multiple filters and I cant afford to go buy a good cannister right now. So I am building my own unit. one I can seal so any offgassing will only be enough to balance the aquarium co2 with the airspace in the bucket. I dont want to try and make a cannister out of this. it'll work the way I am going, how well..... we'll have to see.
Parts (I just want to point out I had all this kicking around the house already so dont ask me how much it cost to build I dont have a clue, sorry):
5 gallon bucket
plastic toilet flapper valve threaded adapter to go from 2 1/2 inch flapper thread to 2 inch PVC pipe
3 inch long piece of 2 inch pvc pipe
2inch pvc 90 elbow.
1/2 id. rubber hose
1/2 od. barbed nipple cpvc
3X 1/2 90 elbow
couple short lengths of 1/2 id pvc.
bioceramic beads gravel and laterite (enough to give a 1 inch deep layer on the bottom of the bucket)
100% polyester quilt batting 1/4 inch low loft 48x36 inches
piece of eggcrate large enough to cover level of bioceramics
step 1: I cut a hole in the bottom of the bucket off to one side to allow the flapper valve throughand screwed the threaded nut tight to get a good pressout on the internal rubber gasket. removed the rubber flap, chain, and top ring off the overfill tube. Left the overfill tube on, in case bottom drain somehow becomes partially or completely blocked to prevent bucket from overspilling
step 2: thread adapter from 2 1/2 to 2 inch onto the bottom of the flapper valve. insert 3 inch long pvc pipe attach 90 elbow. these are only pressed togetheras they dont need to be watertight the bottom of the flapper valve and threaded adapter are below the tank rim, its also low/no pressure so I dont have to worry about that, will also make it easy to modify later.
step 3: fill bottom of bucket with bioceramics up to about 1/4 inch below the lip of the 2 1/2 inch opening. cut egg crate to fit down past overfill pipe, and all the way down to rest snug against the sides of the bucket touching the biomedia.
step 4 cut poly fill to desired shape and stack multiple layers. (I used the whole package so it has about 12 layers of polyfilter. as the polyfilter gets dirty I will remove the dirtyest top layers and replace them by putting new sheets on the bottom of the stack.
step 5: attach maxijet to the rubber hose, create n shape with the 3/4inch pvc and attach to cpvc barbed fitting and attach to other end of tube.
right now this unit is in testing I have NOT cut the hole in the side to allow me to pass the rubber tubing in and seal the top. I want to run it a bit and see how it goes lidless so I can watch the guts and see if I need to do anything else or modify it.
After about 20 minutes of observation I am thinking a bigger pump would be nice. at 14 inches of head pressure the maxi jet will (Head Loss Calculator developed by Jason Nugent, with pump curve information courtesy of Shane Graber and Reefs.org http://www.reefcentral.com/calc/hlc2.php
) ony be pushing about 175 gph that on filtering 1.4x an hour. I want more.I'm going to have to dig around and see if I can mate up one of my bigger rios for the job.
If I can get my camera to work (doubtfull) i will post pics :edit: I got it working
I know everything is croocked I ned to recenter my lights and set up a stand for the SOB. I love that acronym. I think I may cut more eggcrate sections to hold layers apart in the polyfilter, AND add a layer of mat batting as well as a filter sock.