The acrylic arrived yesterday for my next experimental scrubber, so I got started on building it last night, and finished it today. It operates in a similar fashion to a prior scrubber I had 3d printed around a year ago. I'll jump straight into the pics. Below is the base of the scrubber, you can see the crossbars at the bottom, covering the screen mesh. The mesh is there to stop any algae from being drawn back into the motor outlet when the pump turns off, the mesh can be removed and replaced if it needs to be cleaned. Not shown here is a small hole which acts as a drain when the pump turns off. I was hoping that the water would flow back through the pump, and essentially drain itself (as it's mounted above the water line). It did work, but took around 30 seconds to drain, so I drilled in a secondary hole, just above where the top crossbar is above the mesh, it now takes less than 15 seconds, so will fill and empty twice every minute. Since the base plate for the algae growth covers this whole bottom area, it will be blacked out, so algae growth shouldn't be an issue down there. The clear 2mm acrylic covering the magnets etc was supposed to be black (the laser cutting company stuffed up). The scrubber base is designed to sit on the water line. Fairly obvious but this is the growth compartment, water can enter in the gaps around the bottom of the sides, and empties from the same place. The gaps are fairly large, so I'm confident that even with a tonne of algae growth in here, the water should still empty with no problems. If worst came to worst, and water couldn't escape, it could just drain at the top of the sides, it wouldn't overflow the whole scrubber or anything. Growth chamber installed in the housing. The 2mm clear acrylic at the top (should have also been black), where the water overflows, houses a 6mm acrylic rod down to the base of the scrubber. I'm planning on putting a float magnet around this rod, and a hall sensor in the LED area above it will detect if the float magnet is too close (meaning the overflow drain is blocked), and if so, the pump can be switched off. It's really unlikely this would ever be blocked, but I think it's best to have that safety measure in place, just in case. Intake hose barb shown, output from pump connects to this. LED side the scrubber. Just using the previous LED board I got made, will get a new version made to suit this scrubber better. Scrubber will LED lid on, the screws won't be there in version two. Also, the LED lid will be waterproof, this version is just to test the concept. Scrubber installed with mounting bracket. The PCB, power input etc will eventually be mounted on the mounting bracket. Video:
Getting some green tinges around the edges, I realized a couple of days ago the intensity was much too high, so have dropped it down.
Giving the screen a clean today. The growth is fairly slimy, I think because of the fairly high nutrients in the tank.
A few days later and the growth again is pretty dark and slimy. I can only assume the slimyness is caused by the high nutrients in the tank, I tested the phosphate today and the reading was 0.7ppm. Got some more phosphate removing media on the way. I'm thinking of setting up another tank, a smaller one, and testing the scrubber on that.
Gave the screen another clean today, and moved it to a new small tank tank, seeded with some GHA from the other scrubber screen. Some dark brown algae growth was appearing on the screen, due to the rather high nutrients in the tank. Hopefully now that the scrubber is in a tank that has low nutrients, I should start to get some hair algae growth, instead of slime algae.
Almost a week after being cleaned there's green and brown growth on the screen. Hoping that as the nutrients in this small tank are pretty low, I'll start to see GHA appear over the next few weeks.
Still slime, nutrients are low in the tank now, so hoping that will change at some point. I don't have gha growth in the tank though, so not too worried, just a bit frustrated.
Finished building version 2. Other scrubber taken offline. Not running in the tank yet, will be soon though. The main changes: LED control board changed, buttons control it now instead of a wireless remote. Pump built into the housing. Much cleaner looking now. Removal of brackets. LED control side is held in place via magnets and two strips of silicone. Scrubber side is held to place via magnets. I need to add another pair of magnets to this design though. Screen is made from an acrylic base, super glue gel and aragonite sand. This needs testing, but the super glue bonds extremely well to the acrylic and sand, I just need to make sure that over time the glue, or sand, doesn't dissolve. Foam replacing the previous plastic mesh, which stops particles clogging the pump. Removal of hall sensor integration, addition of rear emergency overflow. A few pictures. Still no GHA in my tank. Nutrients are for the most part quite low, I have a fair bit of cyano, a small amount of green algae covering parts of the sand (no more than 1mm thick). I guess it's a waiting game for the GHA.
As the cyano is dying a horrible death, I think I see a patch of gha in its place on the back wall. Would never have thought I'd be so happy to see some algae growing in the display tank.
