Next, I used some white copy paper and traced the outline of the filter housing to make a bulkhead template. I cut out the template and transferred it to some acrylic that I bought from Home Depot (if you plan on trying this, I recommend getting the cutting tool for acrylic, it saves time and headaches). I used a dremel tool to smooth the edges and get a good fit.
Here are the bulkheads siliconed in place. The middle space I added for my 50 Watt heater, so I could get it out of the display tank.
Here is one with the heater in place.
