Printed circuit boards and LEDs arrived

Found two packages in my mail tonight when I came home from work. One box was from BatchPCB.com and the other from SuperBrightLEDs.com. Next thing to do is to solder the parts on and test the design. Hopefully I can find some time to do this in the next few days.

Not hydroponics but dirt gardening

A lot of the basics of gardening are helpful to hydroponics.  If you are interested I have started a blog on my traditional garden.  You can check it out here:

SWF Home Garden

Status update

Currently I am in a holding pattern waiting on parts.  The Chard has continued to grow but is looking pretty bad.   The leaves are growing but it is still sick looking.  Later this week I should be receiving professionally made circuit boards from BatchPCB.com.  No more point to point wiring to deal with.  Also a order for blue LEDs has been placed with SuperBrightLeds.com.  I am trying their blue 15 degrees RL5-B5515 5500mcd LEDs.  Hopefully they will be in by weeks end also.  Other changes I may make is to use a 12 volt DC Radio Shack power supply.  The 12 volt AC toy train transformer is under suspicion for burning out the blue LEDs.  I did multimeter it and it is reading 12.2 volts after the bridge rectifier.  I am interested to see what the new array will do.  I may also build another bubble bucket if I have enough red, orange and blue LEDs for two arrays.  It would be interesting to see a commercial nutrient solution vs my 'solution'.  This blog is called Hydroponics Experimenter for a reason.  Til next time.

Failure or not?

Well my plants fell over on it side. I think the leaves became top heavy when the second set of leaves started on the plants. One of two things happened. One I had the LEDs too high and it caused the plants to grow up into the light too fast. In other words not enough light. Two the nutrient solution was not right. On a high note the plants started upwards again. Once I find a new source for blue LEDs I will try again with the same seeds.



Failure is not always a bad thing as we learn from it.

5x5 LED grow light problems

Twice now the Blue LEDs have burnt out.  The first time I had figured the out that I used 30 mA instead of 20 mA when calculating the size of resistor needed.  At 30 mA the LEDs called for a 270 ohm resistor and at 20 mA a 330 ohm was required.  I figured I had burnt them out with to many volts going through them.  So a 330 ohm resistor was used when I soldered in new blue LEDs.



The corrected parameters also lowered the mA to 200 and the mW to 2477.  But 4 days later they burnt out again.  These LEDs were bought from ledshoppe.com and cost $7 for 100.  This is a good example of you get what you pay for.  I could every 3-4 days solder in new LEDs but for now I am going to leave them out til I can order some others.



After 7 days of being in the hydroponic setup you can see significant growth.

Swiss Chard - First attempt.

So I am starting with Swiss Chard Neon Lights Mix from Burpee seeds.  A one inch rockwool cube was prepaired by soaking in water.  The package said to use a seed starting nutrient mix or a some lemon juice mixed with water.  I did not do that, just water.  Two seeds were placed in the cube and the moist cube was put in a Ziplock bag.  It is important not to seal the bag all the way.  Leave it so air can get in.  Placed it under a CFL light and let sit.  Package said the seedlings would emerge in 7-10 days it took 3.




The seedling is hard to see due to the humidity.  It is on the right side of the bag.  After 7 days the rockwool cube was transferred to the net pot.  First the net pot was filled with expanded clay balls.  The clay balls were then washed to get rid of any of the clay dust.  A hole was dug in the center of the clay balls for the rockwool cube.  Once the cube and clay balls were in place the system was filled with nutrient solution and the net pot put in place.  Turned the LED array on and now to watch it grow.

Hydroponics setup

This is a diagram of my hydroponics setup.






This is what is called a deep water culture system.  A net pot filled with expanded clay balls sits in about an inch of nutrient solution.  The air stone below supplies oxygen to roots.  Capillary action draws water up though the expanded clay.  Roots from the plant will grow and sit directly in the nutrient solution.  My setup uses a 3 gallon plastic buck from Lowes.  Two holes are cut in the lid.  One for a 5" net pot and the other for a fill hole.  Most systems don't have a fill hole but I put one on so I could draw out nutrient solution to test pH without removing the lid or disturbing the plant.  The sight glass on the side allows me to see what level the nutrient solution is at.  It is made from some pvc fittings and 1/2 ID clear tubing.  A drain is on the other side which allows me to remove the nutrient solution before removing the lid to clean out the bucket.  It is not necessary but makes it easier to move.  The air stone is held in the center of the bucket with silicon.  In the near future I will post a step by step on how to build and a complete list of parts.

Air stone at the bottom of the bucket.




The air stone in action.

5x5 LED grow light, part 2

In the last post I showed the schematic and explained the components. Now I will show the prototype I built on some Radio Shack perf board. First pic is the business end of the grow light.  It is a 5 by 5 grid of 25 LEDs.





The view from above shows the LEDs glowing through the back of the pcb.  You can see that the orange lights are arranged in a pinwheel formation.  The two blue lights are visible in the center also.  Point to point wiring on perf board was used instead of etching a pcb.  Took about 1 hour to solder together.





The array is rated at 210 mA and 2607 mW.  For a power source I have a 120 VAC to 12 VAC plug in wall transformer from a toy train set.  In order to use it I had to put a bridge rectifier to convert it to DC.  I realize I did not need to do that since the LEDs are diodes but in my experience it makes the LEDs last longer.  Last but not least I had to have a system to raise and lower the height of the grow light for when the plant grows.  It is about as low tech as it gets.  A piece of wood that the grow light is screwed to with a clamp holding it in position. 

5x5 LED grow light, part 1

So this is what I have come up with for a 5x5 (25 LED) grow light.  In researching the web and the USPO I have found that most of these lights use the following light wavelengths.  660nm for the red, 612nm for orange and 460 for the blue.  Most designs are a mix of 61% red, 32% orange and 7% blue.  My design is for 25 LEDs I will be using 16 red, 7 orange and 2 blue.  That will give it a mix of 64% red, 28% orange and 8% blue which is pretty close.  Also at the time I bought my LEDs I could only find 620nm orange and 465 blue.  They are listed as dominant waveforms so hopefully they will work.





The red 4 led strings use 82 ohm resistors.  Orange 4 led string uses 270 ohm and the 3 led string has a 390 ohm.  The blue LEDs use a 220 ohm resistor.  Part 2 to come.

An Introduction

Being as this is my first post on hydroponics I thought an introduction was in order.  First let me state that I have no background in hydroponics or gardening.  I have however successfully grown vegetables in the ground and with self watering containers.  My interest is in food production and eventually making it a total off grid system.  The plan is to design and experiment as I go along.  First thing that I am undertaking is a LED lighting fixture.  For a hydroponic setup I am using a 'deep water culture' system.  Each component of my system will be explained in further posts but in the meantime enjoy a picture of my setup.