I converted my tanks over to LEDs about ~3 years ago. Since that time, I've faced a challenge maintaining both light loving SPS
and lower light LPS
and softies within a single, shallow Frag tank. Normally, in a deeper tank, lower light corals are placed toward the bottom of the tank and the top, higher PAR
areas are used for SPS
. In a shallow Frag tank, this option is not available. This is compounded by the fact LEDs are very good are producing and delivering very large amounts of PAR
variability is possible by placing lower light corals along the perimeter of the tank, but depending on the size and type of lighting used, this may still not provide enough range. You can vary the height of the fixture above the tank, or lessen the PAR
output through dimming or in the case of T5s, turning off certain tubes, but this lowers the PAR
at the top of the tank as well. I came up with a very simply, DIY solution.
First let me apologize for the poor quality photos. I had left my DSLR at my office and had to use my cell. Although I really like the Galaxy Nexus, the camera leaves much to be desired. This is a shot of my tanks prior to the new racks. The DT is a 24"X20"X20" Cadlights and the FT is a 24"X20"X8" Advanced Acrylic sharing a common sump. The DT is lit by AI LEDs. The FT uses a MaxSpect G-2 160.
I've been using Blue Glow frag racks which are very well designed and built, but don't offer the ability to vary PAR
as much as I wanted. To complicate matters, my Frag tank holds about 240 individual Fags (I had to add 3 magnetic Frag racks to hold everything) so the racking system had to be very space-efficient.
I removed the existing Blue Glow and magnetic racks and installed 1/4" square acrylic rails along both sides of the tank using Cyanocrylate. The rails were placed at 1 1/2" and 4 1/2" above the bottom of the tank.
I then cut black egg-crate so that it would rest on the rails...
I divided the bottom section into 3 pieces, each 6" in depth for ease of removal and cleaning. The top "shelf" was fashioned from a single 6" egg-crate section allowing room for it to slide back and for to adjust the PAR
/shading for the lower light corals placed below the top shelf. The ability to move the shelf also provides easy access to Frags on the lower level. Further PAR
fine tuning is done by varying the number, size and placement of Frag (or empty Frag plugs if desired) in the top shelf.
I fashioned small pylons to support the bottom shelves as they bow under the weight of many Frag plugs and corals...
The top shelf bows slightly, but not enough to warrant additional supports as they contain far fewer corals and smaller plugs to allow light to reach the corals on the lower level.
This has only been in place for a day, but I'm already seeing benefits,
- I now have the ability to create a custom light environment for each type of coral. Lower light corals such as Zoanthids already appear larger and more colorful.
- The egg-crate allows for more flow and fewer areas for detritus to collect
- Because the entire system is modular, it's easy to remove any section for cleaning, or alteration.
- I'm now able to use differing size frag plugs/disks tailoring the size of the attachment area and amount of shade desired.
- Higher coral density and better flow. I'm able to fit more Frags into the same space and whereas before most of the open area was below the rack, now the open area is above the racks which provides for much improved flow over the frags.
Here's a quick video showing the travel of the top shelf...
Ultimately time will tell, but thus far I'm very excited about the results.