I thought I would create a new build thread documenting my DIY Algae Turf Scrubber. Even though it's just one piece of equipment, there was quite a bit of planning, designing and testing before I finished the final project. Background: It's been well documented in my build thread that my reef system has had issues with high nutrient levels. I've attacked the issue from many angles from carbon dosing (NO-POX), supplemental biological filtration (ceramic media blocks) and replacing my initial/aged sand bed. With varying success on each of those methods, the nutrient levels still had a way of rising back to unacceptable levels. Why? My latest theory is that my system is overstocked; and has been for a long time. I don't overfeed my fish, by any means. I strictly feed frozen foods on a daily basis and small sheets of nori once or twice a week. I thaw the frozen foods in tank water and add the mixture directly to the tank; no rinsing. I believe that rinsing the food removes much of what the corals could consume as a food supply. I've created a problem that my filtration system couldn't handle. I've been a huge advocate for using a protein skimmer as a way to remove organics from the water. My skimmer does an amazing job at creating a dark, thick and pungent skimmate. Even though the skimmer is rated for a tank my size, I now realize that it isn't capable of keeping up with my bio-load. I briefly looked into upgrading to a larger skimmer, but with the number of hobbyists turning to an algae scrubber for nutrient removal, I thought I would give it a try. Researching and reading through the ATS threads by David, Gary, Tim, William and many others gave me the information and decision to make my own algae turf scrubber. Criteria: Since I have the burdening need to make everything look and function perfectly, I needed to figure out just how I was going to add an ATS to my system I made a list of criteria that the scrubber had to meet. The ATS needed to fit inside my sump and stand. The ATS would need to sit above the sump to avoid getting submerged during water changes or power failures. The ATS needed to be easily maintained and cleaned. The ATS needed to work. Conflicts: Meeting the initial criteria was an easy task, but there were a handful of conflicts that I needed to consider before designing the ATS. Very limited size and location inside my sump and stand; without replumbing my system. Minimal LED light spillage from the ATS. ATS screen removal and maintenance. Design process: I really wanted to have a two light system so that both sides of the screen were lit, but I didn't have the room so it was going to be a single LED fixture. Since I couldn't remove the screen from the top of the ATS, I knew it had to be removed from the one end. In doing so, I knew that I had to have a way to prevent the water from pouring out the opening. My solution was to make a clear box that housed the screen; it's like a drawer that can be removed from a cabinet. And I still wanted the top of the ATS to be removable as I would need access to the plumbing and LED fixture. To keep the ATS above the water in the sump, I designed the box to sit on the inside lip of the frame of the 40BR sump. I don't have to worry about the ATS falling into the sump as there is only a 1/16" gap between the ATS and the frame of the sump. The ATS fits well enough that it doesn't move much after being installed. I ordered my LED fixture (300w Dimmable Grow Light) before I started designing the interior of the ATS. I needed to know exactly the size of the fixture and the area of the LED array. I designed the interior screen box to maximize the amount of area the LED fixture could light while keeping it confined into the limits of the ATS box. And I also needed to know just how much venting and access I needed for the LED fixture. To protect the light from any contact with the water, I have a partition inside the box that has a clear polycarbonate window sized to the light. To keep the light spill to a minimum, I used black polycarbonate to enclose everything. And to keep the LED fixture cool, I needed vents to allow air circulation in the lighting chamber. I wanted to have the ATS feed pump pull water from one chamber of the sump as I didn't want the pump to recycle any water that just passed through the ATS. And I wanted the drain to empty into my media basket with filter floss so that any loose pieces of algae where caught before entering the return chamber and pumped into the display. I scribbled some rough sketches before drawing up my plans in Illustrator so I could get my dimensions and layout just right. Once the ATS design met my requirements, I moved onto the build process. Build process: I drafted all of the individual pieces in AlphaCAD and then used the CNC router to machine them all. The panels include rabbets/dadoes for all of the joints; I don't like relying on just butt-joints for my projects. I used ¼" polycarbonate for all of the pieces; black and clear. I think there is a total of 18 pieces that make the ATS box and the removable screen drawer. I first made prototypes of the boxes out of clear polycarbonate so that could see how everything was going to fit and work before I machined the final project. And I practiced my bonding skills during this step! I was also able to plan and cut my plumbing pieces at this time. The most difficult part of this ATS design was figuring out how to have the screen be removable yet still be positioned to receive adequate water flow. My solution was to have the screen be held in place by tabs on the lid for the screen box. The screen extends above the top of the box and just makes contact with the spray bar. There were a couple of changes made from the original design before I would machine the final project. I moved the holes for the water supply and water drain. I extended the interior screen box to maximize the usable interior space as it "pushed " the screen further back into the ATS box. I picked up the black and clear polycarbonate, machined the parts and assembled the ATS boxes over the course of a weekend. Once finished, I set up the ATS on an old tank, I hooked up the pump and plumbing and tested the spray bar. I tried a straight slot, a tapered slot, a combination width slot and a drilled spray bar. I found the drilled spray bar to be the most effective. The final project: Here's some of the pictures I took of the ATS after final assembly. The LED fixture side view; drawer closed. There are three openings to allow the cooling of the fixture. There is barely any light spill coming from the vents at all. [URL='http://s32.photobucket.com/user/jason_langer/media/A%20Stand%20and%20Canopy%20Done%20Wright/ATS-Dry-LEDSide.jpg.html'][/URL] The LED fixture side view; drawer open, LEDs off. The LED fixture side view; drawer open, LEDs on. Top-down view; top removed. Drilled spray bar in use. Being satisfied with how it was running, it was time to fit it into my stand and sump. As you can see, there's not much wiggle room inside the stand. The ATS fits just between the power strip and the return plumbing. The drawer to the ATS fits just under the top rails of the stand and are just above the frame of the sump. When I need to remove the entire ATS, I need to disconnect the water supply tubing and the drain plumbing. As the ATS slides out of the stand, I just have to tip the ATS to allow the bulkheads to clear the sump. Operation and maintenance: I seeded the algae screen with some algae from David. To prepare the screen, I used a hole saw bit to scour both sides of the plastic mesh. I applied just enough algae to the screen to see how well the algae stayed on the screen. Satisfied with the initial seeding, I let the ATS go to work. When I need to harvest the algae, I turn off the water supply pump and slide out the screen drawer. The screen box is made so that it holds the algae and any water inside so that it doesn't drip all over the place. I take the lid off the screen box along with the screen covered in algae. I scrape the algae off the screen and place it back onto the screen box. Slide it back into the ATS, turn on the water supply pump and it's back in business; very quick, very clean and very easy. Initial thoughts: I like it. I think I was able to create an algae turf scrubber that addressed my criteria, resolved my conflicts and met my expectations. Aesthetically and physically, it passes. Now, it's time to see how well it does functionally. I plan on keeping this thread updated with how the filter performs and if I do any changes or modifications. Any feedback, questions and thoughts are encouraged. Thanks for reading and following along.