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flush or protruding above the top of the tank, the distributor tube is not nested correctly in the
recess at the bottom of the tank.
Add enough water to the tank to cover the lower distributor with a minimum of 6 inches of
water. This will prevent damage to the lower distributor as gravel is loaded. Place the funnel
into the tank so that the riser tube is in the middle. Place tape over the open end of the riser
tube. This will prevent gravel or media from accidentally going down the tube during the
following steps.
For the following steps, we recommend that you wear a dust mask. Take the bag/box of
gravel and, using a small scoop, add the gravel to the tank through the funnel to completely
cover the lower distributor. Use all of the gravel. Be sure to provide some downward
pressure on the riser tube while adding the gravel to ensure that the distributor does not shift
out of its recess or rise up. Ensure that you create an even layer of gravel across the bottom
of the tank. A rigid piece of thin wall tubing (conduit, copper pipe, etc.), approximately 1”
longer than the tank height works well as a leveling tool if you need it. Ensure that the riser
tube remains centered in the opening at the top of the tank.
