Concept:
While researching commercial algae production for food, bio-fuel and waste treatment I discovered that many designs grow algae in tubes. These are generally clear acrylic tubes of various diameters and lengths exposed either to direct sunlight or purpose-designed artificial lights. As aquarists, we all know that nuisance algae grows in clear vinyl and PVC tubing even when light is less than ideal. So why not grow algae purposely in tubing exposed to optimum light to try to duplicate the commercial designs?
Most of us don’t have space to set up a large array of straight acrylic tubes. So I thought maybe a coil of clear tubing contained in a bucket with an LED array in the center directed through the surrounding coil of tubing would duplicate the conditions. This tubing/light array could then be plumbed to a primary filter or directly to the aquarium tank.
Build:
22’ of 3/4” ID clear PVC tubing coiled inside a 5 gallon plastic bucket. Unions attach to both the input and output so the bucket can be disconnected from the rest of the filtration system. In my case, that is an MBBR in a 10 gallon Brute garbage can. If you haven’t already done so, you can see both of my MBBR filters here:
http://algaescrubber.net/forums/show...r-combo-filter
You can google “MBBR” to find out more about them if interested. They were developed for small aquarium use by the guys at Tyne Valley Aquatics, who seem to have rebranded themselves as Filter Pro, specializing in filter media:
http://filterpro.co.uk/
I bought 25' of 3/4" clear PVC tubing and prior to doing anything else with it, I pushed a Dremel 3/4" wire brush through it 12 times to roughen the surface. After each of the last 6 pass-throughs the brush had an attached ring of plastic fluff, so I conclude this was successful. I then determined that only 22 of the 25' of tubing was usable and cut it. A 3/4” ID tube of 22’ length has an inner surface area of 622 sq in. With my 80 gallon fish tank, this gives me 7 3/4 sq in per gallon of water, which seems adequate with a large margin of error based on the Scrubber Quick Guideline and assuming it’s basically a horizontal scrubber: http://algaescrubber.net/forums/show...E-SCRUBBER-FAQ
I attached 1” ID PVC 60º elbows with male adapters to the ends of the tubing to connect to the input and output lines. The male adapters are 3/4” ID and they fit very nicely into the slip ends of the elbows. On the inside, I glued 1” ID tubing over the male threads with PVC cement. The 3/4” tubing slides into the 1” tubing, and is secured by cable ties. I put hard plastic tubes from a sponge filter drop tube into the 3/4” tubing ends so I could tighten the cable ties without deforming the tube. Note: this photo was made prior to final finish of the connections, so it shows the temporary stainless clamps and tape. The outside threads attach to 3/4" unions.
I built an array of 6 LED panels supplied by ExpressionsLTD, using the base plates of 2 plastic humming bird feeders I purchased from Walmart to support them.
Here’s a view of the tubing and LEDs mounted in the middle of the bucket with a threaded rod through the bottom of the bucket to the top of the LED support. When this photo was made the unions were only screwed on loosely so I could remove the tubing.
My original plan was to paint the inside of the bucket gloss white and put a layer of aluminum foil between the tubing and the bucket walls to reflect light. Unfortunately, the paint scraped very easily and the foil was impossible to position without crumpling a lot. So I discarded this bucket and assembled everything in a new bucket in which I lined the inside with white bristol board.
The scrubber is powered by a Sedra KSP-2000 water pump with an airline blowing directly into the pump intake port. All the commercial designs I examined injected pure CO2 into the water to enhance algae growth. I don’t have a CO2 system and did not want to add to the initial costs of this experimental unit buying one. So I opted to blow plain air into the system instead. The pump sits on the bottom of the Brute. The plumbing:
Here’s a photo of air bubbles traveling through the tube. The flow is counter clockwise from top to bottom. The flow is sufficient to push the air all the way to the bottom and out the outflow port.
Here’s the unit in action. It has been operating since Jan01/16::6:00pm.
I welcome any questions and/or comments.
Now to see if the unit will grow algae, if so whether or not it's sufficient to reduce nitrate and phosphate in the fish tank, of which there are an abundance.
Water params as of Jan03/16:
1. pH: 7.0
2. Ammonia (NH3): 0.0
3. Nitrite (NO2): 0.0
4. Nitrate (NO3): 40+
5. Phosphate (PO4): 10.0
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Originally Posted by SantaMonica
