Necessary shade

For many years, I've used foam sheets from Hobby Lobby (most hobby craft stores have these) to keep the refugium light off the rest of my gear. People often think they need colored or black acrylic in their sumps to avoid algae growth in other compartments and within their skimmer / reactors. However, that's really not the case. While we can see light in the other zones, what happens initially is the light bounces off the acrylic baffle and goes back into the refugium zone. 

And as the macro algae grows and fills the zone, even that is obscured.

What is best is to block the way the light shines sideways through the air, above the baffles and waterline. Back in 2011, I found this foam and it was dirt cheap. $0.99 each, and I only needed three pieces for my project. The velcro cost more than the foam sheets. It held nicely, and I was done.

However, the heat of the light fixture weakened the glue of the velcro strips and they began falling off. You can see how it was looking in this picture.

From time to time, I tried to just press it back on the light which was a temporary fix. I didn't really like the idea of using new velcro since the light fixture was already gummy from the old glue and I knew it would do the same thing again in 9-12 months.

This time, I decided to try something different. I cut out a couple of black pieces of polycarbonate 48" long x 2" tall first, edged them so they were nice and smooth, and used a hot glue gun to affix new sheets of foam to one strip. Once done, I glued the second strip on top, sandwiching the foam. The reason for the acrylic was to keep the sheets hanging straight.

Next, holes were drilled for hanging 7" from each end. The doubled black acrylic will stay straight, avoiding a big bow in the center even as it stands the test of time.

Thinking like the King of Overkill, I bought a spool of 50lb test fishing line. Using fishing line, I could hang it from under the stand invisibly, and knew it would never rust like wire cabling. The sturdy fishing line was thicker too, just easier to work with.

The fishing line was tethered to the same connection the light uses, but now the shade barrier won't touch the light. No more heat issues and melting bonds. I used a type of boy scout knot that would allow me to raise or lower the shade barrier, which also helped me get it perfectly level. We all love it when something looks perfect, right?

Much better.

I did this project June 2015. It's a year later, and it's still in great shape. I need to clean off the foam of salt creep, but more importantly all my gear in the rest of the sump is algae-free. The refuguium was completely drained, cleaned out and reset a few months ago and looks much cleaner.