Hi,
The picture is too small to see. Can you make it bigger?

Sorry - I didn't know how. Try this link.

http://adobe.kodakgallery.com/I.jsp?c=129waay5.w4ll19p&x=0amp;y=-k93tqm&localeid=en_US

If you can, try to put the drain on the bottom of the barrel. You may have to raise the barrel on blocks or bricks. I have my drain on the side and I regret it. It never fully drains and muck stays in the bottom. I have to take all my filters/ grates etc. out of the barrel about twice a month to clean out the bottom.

My boyfriend suggested I turn the barrel upside down because the top has two places for outlets on it, so the drain would be on the bottom. I had already planned on sitting the barrel on a foundation but it is only 6" tall, which may not be enough for the drain to clear. If it is, I could put an extension on it so I could reach the on/off handle. Other than that, any other suggestions/comments???
Thanks.

If you are going to put a drain in the barrel make it no less than 1½" pipe size, as anything less will plug up with silt and gunk.
Of the two "bung holes" located in the top of the barrel, one is either 1½" or 2", [I cannot remember which at this moment] and will accommodate threaded ABS pipe fittings.
You would require a suitably sized valve, installed on this line to allow for draining the sump.
"Horton"

horton,
the "bung holes" are 3". If ABS pipe fitting, or PVC fitting will fit it, how about if I reduce it down to 1" so I can hook a 1" hose to it?

My filter is very similar to yours. I have two outlets using 2" pipe at the top to prevent any overflow if one gets plugged by leaves or something. I also have the pad at the top as the final scrubber for the water. How do you plan to keep the center pipe centered? I used the lid that came with my barrel and cut a hole in it for the tube. Check out my drawing.
{{gwi:205834}}

Kaysbelle. The barrel I used has both 3" and 2" holes.
You can buy reducers to bring it down to any pipe size you want to use.
I found with a filter that I built sometime ago that a one inch drain pipe tended to plug up with sludge quite quickly. I had to keep clearing it out by pushing a wire up into it.
Attaching a hose to a 1" drain, would in my opinion, heighten the plugging problem, as there is no pressure behind the out flow.

You could pop a 1½" hole in the bottom of your barrel with a hole saw and an electric drill, quite easily.
"Horton"

Kalevi - I planned on putting a center hole in the milk crate which will sit in the bottom, then the pads, a bread tray with a center hole, my scrubbies and another bread tray with a center hole on the top.

Horton - I don't really trust my "bung holes" to be leak proof, so I think putting a hole in the bottom sounds like a better plan. I have 1 1/2" PVC fittings from another, small "skippy" filter I can use. Thanks for your help.