Welcome to The Tube

Contact:
RixDobbs@yahoo.com

Let me introduce myself. I'm Rix Dobbs. I've been developing this 'Nutrient Film Technique' Hydroponic Unit for a couple of years now. See Wikipedia under NFT - hydroponics - that's MY unit under development.

	I keep using it because it's so dammed easy and productive. So many folks have shown interest in it I've started making a few for others.

I usually start with plants from the nursery store. I cut off the plastic shrink-wrap and sometimes the fiber cup, too. This is the size of the plants in March in Durham, NC.

   This is a nice picture. Thanks Ildar. (All pictures copyright © Ildar Sagdejev. Click here to see Ildar's Photography.)

   See how the 'net pots' hang nicely inside the tube. Inside, the atmosphere is 100% humid with nutrient squirting sideways (pee-ing - giggle) against the 'net pots'.

   Eventually the roots grow through the pots and hang down into the river of return nutrient on the bottom. When this happens, the plant will be able to persevere with nutrient from the floor even if the squirter holes plug up.

The water evaporation inside makes the temperature cooler than outside - and the foam core PVC insulates it a bit.

	Here's a view inside showing the 'squirter tube to the left - with cork in it. You can take the cork out to flush it out and to run a brush through the tube to clean out the squirter hole plugging debris.

I'm going to sell these at
Stone Brothers Nursery on Washington Street in Durham, NC,

To help educate you I include and audio book on Hydroponics that is playable on any audio CD player. I'll also make MP3 'podcasts' available as a download from this website. I'll make a video for YouTube showing you how to set up and operate the garden.

Future link to the podcast of
"Hydroponics" the audio book.

In a couple of weeks the roots have grown through the bottom of the net pot. When the roots hang down into and drag through the current of nutrient returning to the drain to the tank it hardly matters if any individual squirter hole gets plugged up.

See how nice and pale the roots are. These have never been allowed to dry. These look good.

This is lettuce growing.

	This is the other end of the squirter tube. This is where the fountain pump is connected by a garden hose connector. Easy to connect - disconnect - by hand. If you move the unit I would unplug the pump - disconnect the pump from the squirter tube. Then move it in two pieces. That bucket of nutrient is heavy.

Here I'm checking the pH of the tap water before adjusting it. I've calibrated the meter using a reference of a glass of distilled water in a clean glass at room temperature. That's my assumption, that it's a pH of 7.

I like my nutrient to be more neutral than this but still a bit acidic. Maybe I'll adjust this up to a pH of 5.8 or 6.0. To do this - add a dash of pH up solution, stir and retest. bring it up by small steps to avoid overdoing it. If you DO you have to option to use pH Down solution to adjust it.

This is 6 gallons of water in the 7.8 gallon food grade white opaque plastic beer fermenting bucket I use for the nutrient tank.

    The pH Up solution. Raises the alkalinity. In theory mixing in anything strongly alkaline - like lye - would, on average, raise the pH number. But why not do it with something that the plants need anyway - potassium; as in a dilute potassium hydroxide solution.

   Then there's the pH Down elixir. In theory mixing in anything strongly acid - like vinegar - would, on average, lower the pH number. But why not do it with something that the plants need anyway - phosphorus; as in dilute phosphoric acid.

   I set the water pH before adding the powdered nutrients - including all the MICRO-nutrients as well. (Like copper, iron, molybdenum,.. )

	This is my Total Dissolved Solids meter. It tells me how concentrated my nutrient solution is. It's measuring the electrical conductivity. The nutrient powder is hydrogyscopic - moisture loving. The moisture in the air will cause it to set-up like cement; but it crumbles back up easily - and it doesn't change its nutritional values.

The unit of measurement is the 'Seimens'. Tap water is usually about 400 siemens - a very low number. With the correct 1/8 cup of nutrient dissolved into six gallons of water - usually the number is 'off the scale' too high. This is how you can measure EXACTLY how much nutrient salts have been removed by the plants. It's a diagnostic tool for when there's a question or a problem.

Here's your quarter cup of complete nutrient powder mix - for a ten gallon tank full. A six gallon bucket with five gallons of nutrient: 1/8 cup. That ratio.

The recommended interval to replenish is weekly - but bear in mind that this feeding schedule is for mature, fruiting plants. For growing little seedlings you KNOW the rate of consumption is less. I've 'gotten away with' leaving the nutrients un changed for a month.

I have them in sawhorse-like stands that fit the semicircle cutout at each end to fit the form of the 6" PVC tube. You need to height so that the nutrient tank can fit below the tube drain for a gravity return. This also brings your work area up to waist high so that you can admire your plants better.

	It's nice to be retired and do something that you love. Something that you enjoy doing in the garage. Right now folks can use a 'Recession Garden'. You can grow $500 worth of vegetables a year. These things pay for themselves the first season. It's my intention that the profit from this go towards funding the construction of my Solar Thermal Power unit and the follow-on invention 'proof of concept' of The Dobbs Device. See http://www.SolarThermalPower.com and my YouTube Video.

Go to the first page of the new owners setup instructions

These are 'Better Boy' Tomatoes. At the BrewMaster Store we're demonstrating growing flowers - all different kinds - on our unit.

There. You can see the streams that constantly water the plants.

... And this is broccoli. Same age as the lettuce.