Comments on: Automated plant growing

By: laszlo

laszlo — Wed, 04 Mar 2009 13:15:05 +0000

Great tips from all the ‘homegrowers’ out there, I have plans of using a PIC micro controller for environment and feed automation (hacked out of a coffee machine :P)

If you are worried about head produced using HPS bulbs, you can use a cooltube, where the bulb is mounted in a glass tube with ducts going in and out of the enclosure and a fan to cool the bulb.

By: bjandthebear

bjandthebear — Mon, 02 Mar 2009 07:33:18 +0000

Very interesting posts from everyone. One thing I would like to “illuminate” is the fact that HPS and MH light bulbs (and I just talking about one) produce SOOOO much heat. I know this from experience. A friend and I had a “setup” in an apartment we were staying at and we used our small bathroom as our grow room. Yes there was an induction fan in the bathroom (which was rerouted, to properly dissipate the “stank”) and Yes we added a large room fan. The high pressure sodium bulb we used still produced more heat than I can explain in words – this is not a bulb you want to be jamming into a closet or super small stealth place. Also im positive that on a FLIR this thing would look like a bonfire in the house. LOL GL all and be careful.

By: space

space — Sat, 10 Jan 2009 22:55:07 +0000

My humble experience on indoor plant growing:
Paint your grow chamber white. That will spread light more evenly.
Add up to 10% in volume activated coal to the soil to help regulate the moisture level. Make your own activated coal form wood or charcoal.
Watch out for mold and be ready for countermeasures.
Add CO2 to your grow chamber if possible.
Make heat exchanger using two pipes of different diameter placed one inside the other. Add small computer fans inside the box to mix the air.
If possible find and watch “Forest Gardening with Robert Hart”. The last 20 minutes of this film is all about tiny gardens, might be of great help.

By: JD

JD — Fri, 09 Jan 2009 17:20:24 +0000

The problem with HID lights is that their spectrum tends to be “spikey”. It is not necessarily producing the light power at the most efficient light spectrum that plants use. By using primarily red and blue LEDs, centered at the optimal growth rate spectrums, you can cut power requirements which also cuts heat requirements. The other issue with HID lights is that they radiate heat. The heat is emitted in all directions, which can be a problem for controlling the environmental factors of an indoor/enclosed garden. LEDs conduct heat, which can be directed into a heatsink or even into a water cooled system, which means you can output that heat wherever you want. LEDs are far more efficient in Lumens/Heat output as well.

And yes, LEDs are FAR more expensive to use as grow lights. However, if you do all the work yourself, such as building the enclosure and power supplies, as a high watt constant current power supply is hard to find and VERY expensive when it is found, you can keep the overall cost relatively close to what you’d pay for a commercial HID setup. In bulk, high wattage (3W) Red and Blue LEDs can be had for roughly $1.50/ea. You can build a high wattage CC power supply for under $25 if you scavenge parts, for instance, utilizing a PC power supply as the main AC-DC converter.

This is Hack a Day right? We’re into hacking stuff and building it ourselves? If anyone is truly interested in using LEDs, also look into FR (Far Red) lighting implications as well. The involvement of Red and Far Red in how a plant photosynthesizes is quite interesting and the growth rate can be substantially increased with its use. As a hint, introducing Far Red light during the first 5 minutes of the dark period allows for a shortening of the dark period by 2 hours. Aka, two more hours of light.

Other areas of interest that I’ve researched personally and am currently piecing together/building is an automated CO2 injection system. By increasing the CO2 levels (in a sealed growth chamber) to 2000ppm (normal air is roughly 300-350ppm), you can increase growth rates by upwards of 200%. I also am building an aeroponic watering system (think hydroponics) that utilizes an ultrasonic fogger, often found in Shaper Images (when they existed) desktop fountains. This fog is actually micro-particles of water (think clouds) and enables the root system to absorb the nutrient rich water at an accelerated rate.

All sorts of fun things you can do with technology and plants. Agriculture was man’s first big technological advance right? Why not mix in some of the newest technology to increase yields.

By: Bryan Ribas

Bryan Ribas — Thu, 08 Jan 2009 13:02:01 +0000

Check out this site: http://www.hobby-boards.com/index.php

By: The Cheap Vegetable Gardener

The Cheap Vegetable Gardener — Thu, 08 Jan 2009 00:45:21 +0000

@Monkey Boy, I have actually considered the lumen meter ticky part is photoresistor part is easy, though unless I have measurements like “Sunny”, “Kinda cloudy” :) If anyone has any ideas on this definately open.

By: Monkey Boy

Monkey Boy — Thu, 08 Jan 2009 00:22:16 +0000

@ino & apu -

Efficiency is not the issue as much as spectrum and lumens. You need the right light at the right levels. HPS is viewed as better than MH for spectrum, and T5 flos are great, but per lumen the same price as other bulbs AND you need more hardware and space to run them. LEDs are pretty iffy right now and insanely expensive. CFLs work well for small setups, but don’t work for all plants the same. Basically more light = more heat and power used so there ain’t no “stealth” system in reality besides not growing more than a few plants of any kind. FLIR on a 4-600w HPS system will show up like a space heater on low or a high-end PC or two (hey, we have 1KW power supplies now…)
Cool rig though. It would be neat to see it integrated with an outdoor gardening system. Or even a thermometer and lumen meter to tell you when to transfer those tomato seedlings to outside.

By: The Cheap Vegetable Gardener

The Cheap Vegetable Gardener — Wed, 07 Jan 2009 23:07:11 +0000

@ino: you are correct normally discharge lamps definately have better lumen to wattage ratio than any other type of lights on the market. But plants can only consume so much of this light, specifically on the red/blue spectrums. Problem is most lights are created for humans in mind who see orange/yellow/green pretty well but not red/blue spectrums. As you can see HPS http://www.astrosurf.org/buil/filters/sodium.png is primarily green wavelength which plants reflect (being green and all) If you want more geeky talk of this I actually have a seperate post on this subject:

http://www.cheapvegetablegardener.com/2008/12/effects-of-colors-on-plant-growth.html

By: dildo baggins

dildo baggins — Wed, 07 Jan 2009 22:27:34 +0000

@ino
I’m pretty sure that there are some CFLs that beat the HIDs (HPS, MH, etc.) in terms of efficiency. I think that Lights of America were the making some of these ultra efficient CFLs a few years back.

By: ino

ino — Wed, 07 Jan 2009 17:22:16 +0000

@apu : discharges lamps are still the more efficient sources of light.
Try to match the output light of a HPS with leds and you’ll have some heat to manage.

By: JD

JD — Wed, 07 Jan 2009 17:12:38 +0000

Ironically, after doing a lot of research over the past few months to do the same thing this person has done, I’ve come to two conclusions.

1.) Only guys interested in growing weed are building / research the best setups for growing indoors.

2.) The best setups are VERY expensive, so the only crop worth growing, is weed.

I’m still going to start my own indoor garden, using LEDs, ultrasonic foggers (aeroponics), temp/humidity sensors, and complete automation, but its for fun. Trying to do it for any other reason (money reasons) just leads to the two points previously made.

If anyone wants/needs info on indoor growing, hydroponics, and all other related items, just go to one of the MANY pot growing sites. Very useful info from a bunch of people who are usually labeled as “lazy and unmotivated”.

By: apu

apu — Wed, 07 Jan 2009 16:16:15 +0000

I want to see some LED based growing systems. Less power and heat has got to be a good thing. Anyone have any good links on these?

By: localroger

localroger — Wed, 07 Jan 2009 13:35:34 +0000

octelcogopod: even if kopbusters narced themselves, what the cops did was still illegal because an anonymous tip isn’t probable cause. It just reduced the amount of time their lawyer had to wait. (and did i mention the lawyer who housesat waiting for the raid must have balls of titanium?)

By: Pheser

Pheser — Wed, 07 Jan 2009 11:03:39 +0000

I once used this “labjack” thing to control electronic devices trough usb. Let’s say it was a more expensive kind of plant i managed with this server setup. The one you need to grow for 11 weeks before you can sell the stuff you harvested :D It worked perfectly.

Measuring ph, giving water and checking the humidity was all done automated. Also installed a cam to check for trespassers. Refilling the water was something done by hand, but the rest was pretty much automated and manageable on distance.

Please note that in my country it’s only illegal to have more then 5 of those plants.

By: octelcogopod

octelcogopod — Wed, 07 Jan 2009 06:54:41 +0000

localroger:

kopbusters submitted an anonymous tip about themselves. it would’ve been a really good project if they let the cops come to them unasked, but they went in a really stupid direction with it and invalidated what they were trying to prove