Yeah, that's your problem. Half inch is very restrictive. The RC calculators don't even include half inch as a choice.

I would suggest redoing it with at least 3/4, using glued PVC. Just because the output on a pump is a certain size doesn't mean you have to use that size - adapt up at the source.

With 3/4 you should get around 150 gph based on a very rough run through the calculator (with guessing). Half inch would be just around the fourth root of that (flow varies as radius to the fourth power I seem to remember) which is about 3.5 gph. ie almost nothing.

Experience is nothing more than a long line of screw ups!!! Have fun.

Just curious...what size is this tank?

it is 25gal cube (18x18x18) with an 8 gal fuge attached directly on the back.

I guess what my problem is now, is that I had 1inch holes drilled, but the bulk heads are 1/2inch.. does anyone know how much flow you can safely run through a 1/2inch bulkhead?

Pipe size doesn't have to be restricted to those on the pump outlet/inlet. You can use bushings to switch to a different size. What I'd do is use at least 3/4" or even 1" ... it does make a big difference.

You could try leaving the 1/2" bulkheads in for now but using 3/4" or 1" on the pipes, and see how it goes. The bulkheads themselves will be a slight restriction, obviously, but it might not be too bad. Failing that you may need to get the holes enlarged, but jump off that bridge only if you have to.

Basically by stepping up the pipe diameter, also going PVC with glued fittings, and maybe stepping up to a Mag7 or a Mag9 even, I'd bet you'd probably get the kind of flow you're looking for. Just my guess though ... always a little bit of trial and error at first when doing these setups.

If I had gotten a nickle for every time I redid my plumbing for every tank, I'd probably have gotten enough to pay for all the extra little PVC bits that I went through!!!!!! :lol:

I would just suggest upgrading your pump to a MAG 7 or 9.

I am looking to push around 15x (or more if possible) the tank volume.....

Well this is my "current" plan (it'll probably change again :rolleyes: ). I am going to plug up one of the holes on the back and put a valve on the other, and use that to drain the tank for wc's.... then I am going to place the pump inside the sump/fuge and use pvc or loc-line to plumb it to the 4 outlets (can't decide between the 2, any opinoins?)... anyone see any problems with this plumbing setup? thanks.

I would plumb with PVC, because its widespread and easy to get. Keep in mind that with mag pumps, its suggested that the user should use a pipe with an id doulbe that of the output of the pump for maximum flow. So if your output is 1/2", using a pipe/tube with an id of 1" would maximum flow. I've heard of several people who've had flow problems with their mag pumps because they didn't use the proper pipe diameter.

If you're going to use the mag as a return pump from your sump, I would personally go with a mag7 or 9.5. Flow can be easily adjusted by adding a ball valve to the output of the pump.

-Richer