Phototron owners are often dissatisfied with the inflexible choice of growing media and nutrients that must be purchased from the manufacturer, as well as the prescribed watering regimen. You can now use their unit with a variety of conventional hydroponic media, nutrients, and active recycling ebb/flow subirrigation. Because safety is given top priority due to the location of electrical components within the unit's base, no modifications are made to the Phototron unit. This article describes how you can use your Phototron as a light source while safely adapting these conventional hydroponic techniques and products to fit your needs and your pocketbook instead of the manufacturer's.
The Growing Container
Buy a plastic Rubbermaid bucket. 9 or 11 quart size. Make sure the bucket is at least 2 inches taller than the tron base is deep. In other words the bucket should stick 2 inches above the base when it is in the base. You may need to squeeze the bucket to get it between the light tubes when you put it in the unit.
At the top of the bucket, just below the lip, drill a hole and find a way to attach a fitting that either a 1/2" or 5/8" garden hose will fit onto. The hole must be above the upper edge of the Phototron base. This is your overflow outlet, the other end of the garden hose goes into your reservoir. The bucket will fill with solution to this point, the overflow then runs back to the reservoir. In effect the fitting will be the high water mark for the bucket. Finding the right fitting was the most difficult part of the project for me. I had to use a brass fitting threaded on one side (would prefer plastic), then found a nut to fit. Put a rubber washer on each side of the bucket, to serve as a seal, before tightening the nut. Use an appropriate submersible pump that is impeller driven. Most Little Giant submersible pumps are this type. The important point here is that when the pump shuts off the solution must be able to siphon back through the pump. Hook up a length of 1/4" black poly tubing to the pump, you'll have to find an adapter or make a manifold for this as described in the Ebb/Flow Hydro System Construction article.
At the end of the 1/4" tubing leading to the bucket you can attach a small plastic tee. However, I strongly recommend you use the simple snap-on assembly shown here instead, and insert it as well as the 1/4" feed/siphon line to a snap-on fitting installed through the side of the bucket just below the overflow. Plastic tees, rigid plastic tubing, and elbows can be found at any aquarium store (or auto supply store under vacuum fittings), black 1/4" poly tubing is found at garden centers with the low volume watering accessories in the garden hose department (tubing must be black). The tubing can be used to tightly join the parts together.
Place the plastic tee at the lowest point in the bucket for complete drainage and anchor it to the side or lip of the bucket so it wont move from the surge of water when the pump turns on. Run it into the bucket at the same place the overflow is located. When solution squirts from the tee it should squirt to the left and right, not up or down. These buckets usually have a slight depression running around the outer wall of the bottom, this depression is ideal for the Tee and will act as a sump. The illustration to the right shows a short length of poly tubing being used to connect a Tee to a section of rigid plastic tubing, which is in turn connected to an elbow. The elbow snaps onto a 1/4" fitting anchored in the wall of the bucket. This simple assembly is used in all the trays because of its secure anchoring, but its function of feeding/siphoning can be accomplished by placing a Tee directly onto the end of the tubing run.
Gaining access to internal tray parts
Next you will need something to prevent the growing medium from resting against the tubing and overflow outlet. Any plastic cylindrical object sliced down the middle, then placed against the inside wall of the bucket will do. Even a short section of vinyl rain gutter will do as a fence of sorts. This allows you to remove the tube and Tee if needed, and prevents the medium from covering the orifices or making the feed/siphon fitting or line inaccessible during the time a plant is growing in the bucket. Since the solution flows in and out of the tee, a natural self cleaning effect is created. It will spit out roots before they have a chance to grow into the orifices, and because the solution siphons up when the bucket empties instead of draining down, there are no drain holes in the bottom of the bucket to leak or be clogged by gravity driven roots.
Both pea gravel and Geolite grow rocks have been used with this setup, each works fine. However, I advise using Geolite because it's lighter and much easier to handle within the tight confines of a Tron. Fill the bucket with some medium and you're ready to rock n' roll.
That's how to turn your Phototron into a subirrigation ebb/flow hydro unit. With this setup no solution ever touches the Phototron base, and the original integrity of the base is maintained for safety.
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