How to Install an Overflow Drain for Protein Skimmer

A protein skimmer is an important part of filtration for any saltwater aquarium. It removes biological molecules from the system in the form of a scum-like foam, which collects in a cup at the top of the skimmer. A skimmer whose adjustment is even slightly out of balance can produce a great deal of scum that can overflow from the collection cup, but an overflow drain will help prevent a mess of spilled foam. This drain, which requires no adhesives and can easily be sealed off at a later date, will work on a skimmer with a large cup.

Things You'll Need

• Protein skimmer with collection cup that has at least 1 1/2-inch space between inner and outer walls
• 1/4-inch FIPTxFIPT (female thread) PVC bulkhead fitting
• 1/4-inch MIPT x insert (male thread x barb) PVC adapter
• 1/4-inch (inner diameter) flexible tubing, about the same length as the skimmer's height
• 1/4-inch MIPT PVC plug (optional)
• Teflon tape
• Drill
• 7/8-inch drill bit
• Marker
• Non-metallic bucket
• Weight (such as a stone) to keep bucket upright, if necessary

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Instructions

1. • 1

     Mark a point on the bottom of the collection cup that is equidistant from the inner and outer walls.

   • 2

     Drill a 7/8-inch hole at the point marked in step 1.

   • 3

     Remove the nut from the bulkhead fitting, leaving the gasket (washer) in place, and push it into the hole from inside the cup. The gasket should be on inside of the cup. Screw the nut on tightly from underneath.

   • 4

     Wrap 2-3 layers of Teflon tape around the threads on the MIPT x insert adapter, then screw the adapter into the bottom of the bulkhead fitting, under the collection cup.

   • 5

     Push the tubing onto the insert (barb) end of the adapter. Place the other end in the weighted bucket.

   • 6

     Add water to the collection cup to check for leaks. If any are discovered, try tightening the bulkhead's nut or applying Teflon tape over the leaks.