Hydro Plumbing by pH

Any "hands on" engineer knows the importance of having a "WELL" stocked assorment of materials to choose from when building anything, especially a prototype. Building ones first hydro system, qualifies as a prototype in my book. Having a "convenient" choice allows one to find the right piece for the job, instead of having to settle for only what's at hand, or making countless trips to the home center or hardware store. I'm also a strong believer in the modular concept, and using "off the shelf" products rather than reinventing the wheel.

As far a hydro plumbing is concerned I believe in using materials that allow me to "easily" change, move, replace, or add any of them at any time. I stay away from anything that requires glueing or otherwise would be considered a "permanent" installation. This allows one to add to their system or modify it without major headaches.

TUBING
I use 3 kinds of tubing, 1/2" for draining, only 1/4" for feeding, all readily found in any garden center. And I always have a supply of each on hand.

1/2" garden hose (can take reasonable bending without kinking)
1/2" block poly tubing (needs elbow fittings or tees to avoid kinking)
1/4" black poly tubing (with 3/16" inside diameter)

The poly tubing is commonly found with low volume watering supplies, usually for outdoor underground and/or drip irrigation systems. Some common brand names are Moisture Master or Nelson Rainscapes. Moisture Master 1/4" tubing has a slightly thicker wall than Rainscapes thereby making the ID smaller and much more difficult to fit over some fittings designed for 3/16" ID tubing, I use the Rainscapes 1/4" tubing for that reason.

Any 1/2" plastic garden hose fittings will work with both types of 1/2" tubing. Fittings (elbows, tees, etc) for the 1/2" poly tubing are special but also readily available.

FITTINGS
Where one finds the poly tubing he will also find fittings to be used with it. Make sure you get the tool for punching holes in the 1/2" poly tubing. One of the best aids I've come across is a package of assorted fittings sold under the Gardena brand name with Model #6203. It contains tees, elbows, caps, end plugs, hole plugs, and end caps for 3/16"ID and 1/2" tubing.

One little known advantage of the 1/4" fittings is that they can be used with "any" soft resilient plastic that you can punch a hole in. This includes tupperware containers, and vinyl planter boxes. When the hole is right they will snap-in and self seal, this provides a good anchor where needed. They have to be cut to be removed. I use this technique to anchor 1/4" feed lines to the bed, instead of running the tubing over the top then taping or clamping the tubing.

MANIFOLD FOR THE SUBMERSIBLE PUMP
When one brings home a pump the first chore at hand is how to adapt it to the purpose(s) at hand. Simply feeding the plants is NOT the only purpose, one must also empty and refill the reservoir routinely. Since the manifold is immersed in nutrient solution all the time you must use non-corrosive materials such as plastic or stainless steel.

The outlets of pumps vary in size so the first thing to do is to decide what is needed to get the 1/2" vinyl tubing attached to the outlet to use it as a manifold.

If your pump has a garden hose thread discharge use a garden hose fitting for 1/2" garden hose (make sure it has stainless steel screws). If it has a 1/4" MNPT discharge you may be able to simply slide the 1/2" tubing over the discharge and fasten it with a plactic clamp, or buy and adapter for 1/2" tubing (both are found at any good water pump or pond supply display). Mine has a 1/4" MNPT so I'll descibe my setup below.

To a very short length of 1/2" tubing terminating with a suitable garden hose thread attach a garden hose "Y" adapter that has a shutoff valve on each of the two sides of the "Y". At least one side of the "Y" should also have a snap-on type of connector to match that on the garden hose you will use to fill and drain the reservoir. The other side of the "Y" will be used as the plants nutrient supply. With this "Y" and its valves you will easily be able to shut off the supply of solution to the plants while using the pump to drain the reservoir. Simply snap in the hose, turn two valves, then turn on the pump to empty the reservoir. You can refill the reservoir straight through the pump just by connecting the other end of the hose to your water supply.

For the plant nutrient supply side. Take a length of 1/2" poly tubing, punch holes, and snap-in the connectors for as many 1/4" feed lines as you need. Use an end plug on one end, connect the other end to the vacant side of the "Y" adapter with a garden hose fitting.

TIPS & TECHNIQUES
Use one unbroken 1/4" line to run from the manifold to the plants/bed. Don't be cheap and use sections of left over tubing with joining connectors, you're asking for a leak if you do.

I find any 1/4" tubing gets less flexible with use. The insides also tend to accumulate a coating over time. For these reasons I replace the 1/4" tubing every few crops or so.

If a tube loses some flexibility and wont hug a fitting as tightly as it otherwise could, use a one inch length of tubing with 1/4"ID to slide over the 1/4" OD tube, then slide it over both the small tube AND the connector.

If hoses are difficult to get on the connectors, heat the hose in hot water first to soften it and make it more flexible. A little petrolium jelly can help too.

click here to read about converting a phototron to hydro