Slim continuous surge scrubber

Alrighty so I posted a couple of weeks back in the 'watch this space' thread about a idea I came up with, and how I was getting a 3d printed model prototype made. Today it arrived.

Here's a few pics of the design. Note that this design is based around the limitations of my wall reef tank. There's also a couple of minor improvements I've made in the time spent waiting for this to arrive.

I'll set it up tonight hopefully, and post some pics in action showing how it works.

 

Just waiting on the plastic coated neodymium magnets that hold down the algae screen plate. That's what those two little blocks with circle holes are for.
Hopefully they'll be here early next week.

Then will chuck up a video

 

Finally got it set up today.



As seen in the video, water fills the chamber, the chamber empties (exposing the algae to air/co2) and the cycle repeats.
I'll probably set it up so that the pump runs for about 10 minutes, then stops for 30 or 60 seconds. I'm not sure, but I doubt there will be much benefit to constantly filling and draining it.

 

I'll try it for every 5 mins and see how it goes

 

It's currently setup to pump water for four minutes, then stop for one minute, so a five minute cycle. Three and a half surges a minute is pretty frequent. Time will tell, but hopefully it works fine, filtration is a massive pain on this tank because of its dimensions.

I'm not expecting a tonne of growth, because the tank itself is only about 10 gallons with 3 small fish, so I don't feed much. But hopefully there's enough nutrients in the water to give it a good initial burst, then I can crank up the feeding and get a couple more fish.

Will post some pics when I start to see some growth.

 

So it's been almost a couple of weeks since it was set up. Nothing much happened in the first week. Second week I've got some growth, some long thin individual strands of algae, along with a bit of slimy stuff.

Interestingly the algae has predominantly attached itself to the 3d printed base, not the roughed up mesh canvas, so I've removed the canvas from the base. Makes no difference really, still just as easy to remove to clean.

The growth was going a bit yellow, so I've reduced the hours down from 18 per day to about 11 a few days ago.

 

Frustratingly my cheap motor driver died yesterday. That meant my pump stopped working, meaning no water on the algae screen so the algae growth got cooked by the LED's. The algae was bone dry and must have been like that for at least 8 hours, so I guess it's dead, but I'm hoping it can magically come back to life.

Luckily I had another motor driver spare.

So back to square one. Just when the growth was starting to look pretty good, and the algae on the rocks in the tank was starting to die. Dammit.

:-0

 

Ten days later it looks like it's taking off. While it's a bit hard to see in the photo, there is decent growth around the edges, but a definite hot spot in the middle after adding another LED. So I've dropped the LED output by a bit under 50% to get the whole screen covered properly before I ramp up the LED's again. The drain small hole has filled with algae, so it doesn't drain anymore. I was going to clean it but it's been like it for the last week at least, algae is growing well so I am just going to leave it to see how it goes. It's no longer a surge design, but seems to be growing algae nicely. I think SM's claims that algae doesn't grow well submerged are completely unfounded. I don't see major reason why a submerged scrubber won't work with decent flow.

 

Five days later and the algae is definitely getting thicker. The middle is starting to fill in, so I've cranked up the LED's again. Looking good so far.

 

I keep tinkering with this and have set up a semi accurate day / night cyle.
The LED's now come on very dimly at 7am, and slowly ramp up to full power at 11am.
At 6pm they start to dim down until at 10pm they turn off completely.

This is only with red LED's, but I could add a white and blue LED to make it more accurate.

 

Will be adding a blue LED when I get a new soldering iron, my old one's crapped out.

 

Update:
Water got in to the LED housing a couple of days ago and some LED's got fried due to a dodgy silicone seal.
If the acrylic screen was just a few mm higher it would completely clear the water and it wouldn't happen. Very annoying but can't expect too much from version one. Got some more LED's on the way, but will be a week or so before they arrive.

On another note, I purchased a 3d printer and some ABS plastic which is be being sent to me soon. I have to assemble and calibrate it, but when it's up and running I can start to print out version two and do some more testing with 3d printed screens.

Also I've got a PCB board designed and on the way that allows for remote control of LED intensity and duration. (Through one of these: http://www.adafruit.com/product/1095)
Uses two Meanwell Ldd-700H drivers that can control 10 LED's each, so 20 LED's total. Should be enough for what I want to do short term.

 

Remote controlled dual LED driver board is complete. Finished the programming tonight, tested it and it works great, very happy with it.
Has a startup mode where over 4 weeks the LED intensity is automatically raised from 40% to 100%. Also the duration and intensity is very easily controllable.
Will be testing a new submerged scrubber design hopefully in the next week. The growth material itself moves, along with the water around it which should theoretically do a decent job on nutrient transfer. Not sure how well it will compare to waterfall scrubbers, but I'm hoping it it will destroy upflow scrubbers and the like, which shouldn't be that hard...

 

Test run with pictures will be coming soon.
Test build will be designed to remove 1 cube of frozen food per day. Paired with a Eheim Compact 600lph pump. Dimensions of the scrubber itself is: 17cm x 8.5cm x 8.5cm (LxWxH). It's neither a horizontal or vertical design. Operates submerged.
Just waiting for the heatsink now, then can finish the LED housing and see how well it works