So what is this algae turf scrubber (or ATS for short) DIY project that I mentioned in a previous post you ask?  In short it’s a type of filter or means of nutrient export.   The theory is to create an area where algae will grow at a rapid rate thus taking up nutrients in the water.  These excess nutrients can cause unwanted algae growth in the display tank, or at high enough levels even create a less than ideal environment which could cause coral health to suffer.  The nutrients absorbed into the growing tissue of the algae are removed from the system when the algae is “harvested”.

Algae turf scrubbers are quite simple but need a few things to work.  Basically, we are trying to replicate a “surf” environment with flow that allows for high oxygen levels and intense direct lighting in the 6500K or natural daylight spectrum.  This is actually my second ATS build.  The first used a “surge” device to mimic surf/wave action, but had some downfalls that caused me to dismantle it and call it a failure.

The basic ATS concept has been around for decades, but the design I’ve worked off this time is a new twist.  The “growing surface” is plastic canvas that can be found in any craft store/craft department. The basic structure is built from PVC pipe and the plastic canvas is fitted to a piece of pipe with a long thin slot in it.  This slot allows a sheet of water to constantly cascade down the canvas.  All of this is mounted inside a container (in my case a Rubbermaid “box”) which contains any splashing and directs the water back to the sump.  Lighting is achieved using two 6500K CFL flood lights.  Using two allows both sides of the screen to be lit, effectively doubling the algae growing surface.

This photo shows roughly one weeks growth.  I remove the screen every 7-10 days and take it to the sink where I scrape most of the algae off using a plastic kitchen spatula.  The nutrients that have been taken up by the algae have now been removed from the system and there is enough algae still attached to the plastic canvas to start the next “crop” growing.

So is this contraption a success this time around.  Well, it’s really too early to say (remember that old saying “nothing good happens quickly in a reef tank?).  At the very least it’s growing algae very well so I think it must be having some positive impact on nutrient control.

Happy Reefing!