Gravity or pressure from the pump is feeding back into the sump area. If you look at the 2 pics showing the sump area you will see the Mag18 that feeds the System and the Mag24 that feeds the reservoir. So as water is pulled from the sump with the Mag24 to the barrel, it is also returned to the same area.

I have to gate down the Mag24 as it is to much flow to the barrel. The barrel is sealed but it trys to expand to much with the pump wide open. The 1" return line from the barrel back to the sump should have been 2" or better I think. Though if I swap the Mag24 out with a smaller one, it should be fine.

The reason I cut the big square hole in the top of the barrel was to plumb the inside and to pour the sand in plus a few rocks. I used a piece of 1/4" plexi-glass to seal it up. I pre-drilled all the holes in the plex and then siliconed all the way around where it would be screwed down. I used a real generous amount and let it squeeze out as I tightened the screws down.

Though the silicon did start leaking due to the amount of pressure on the barrel before I gated the pump down. I will most likely go back and take the plexi off and redo it with GOOP to really glue it down. I have no reason to really remove it now that it is set up and running.

Since it is outside in the garage I will wrap a water heater blanket around it real good, insulating it from the temperature. Plus to keep any light out of it as I do not want any algea to grow in it. The pods, worms and such should migrate over to it soon enough. I can always seed it though through the screw cap on it.

Let me know if there are anymore questions and I will also take any pics if you would like to see better shots and post them.

Mark