Hey everyone. Sorry for the delay in getting back with the final results and the start for test 2. We were enjoying a bit of a holiday.

As you may remember Test 1 suffered a few screw-ups on our part :

- 60 hours less light for the LED test than the HPS test due to technical problems. One thing that wasnâ??t clear was that the 60 hours (5 days) was at the switchover to flowering so the impact may have been greater than just the 10% difference in amount of light between HPS and LED â?? we will see in this 2nd test.

- a month long dropping water level in the basin which raised the temperature of the water and according to Theoreme Innovation can reduce the amount of light output from the lights.

-placing the plants more spread out than we should have.

Plus, we may have had a difference due to a difference in the ambient temperature around the plants comparing the HPS to the LED. One of you found some info that indicated that this might affect final yield results. Thanks a lot for the info.

So as you will see below, we hope to correct these errors in test 2.

So the final dry weight result from the LED was 0.75 lbs. For us this is a great first result. Our best guess (and hope) for test 2 will be one pound and we will work on improving that in test 3.

According to our calculations this yield works out like this :

HPS LED LED
Test 1 Test 1 Test 2
Power (12¢kWh) (goal)

Yield1.4 lb 0.75 lb 1.0 lb
Electricity$94.75 $34.68 $34.68
AirCon $38.77 $13.80 $13.80
Bulb Cost $19.26 0.00 0.00
Ballast Cost $11.42 $25.47 $25.47
Total $164.20 $73.95 $73.95

Cost per lb : $117.29 $98.60 $73.95

Savings to HPS : 15.9% 37.0%

So this is a cool result so far with more refining to go especially since we had one extra plant running under the HPS (6 plants vs. 7) this time.

How did we figure this out :

- we pay 12¢kWh. HPS total to light 789.6 kWH. LED to power 288.96 kWh. You can calculate with your own power rate to see how your figure would be different. Obviously the higher your electricity rate, the higher the savings.
- AirCon : at the time of this test we had air con running. Whether we would need air con at all with a full LED set-up is unclear, but these lamps run really cool so probably not but too early to say. The cost of air con was calculated by a friend who knows about air conditioning. Basically my aircon guy says about 33% of the cost to light would be used in aircon here. Down south I guess this would be a lot higher.
- Bulb costs : ours cost us $129 per year and we change them every year to get the most from them, so every 4500 hours to pick a round figure.
- Ballast cost for the Smartbar is $1895 divided by 50 000 lifespan x 672 hours for this test. HPS is $850 for a full set-up of reflector, ballast etc lasting the same time as the Smartbar of 50 000. Maybe using 50 000 for the ballast is not realistic as that would be about 11 years. Does anyone have any feedback on this part?

Test 2 Set-up
You can see the new set-up for test 2 in the photos.

What is different?

- We put a fan on the water basin like on Experiments with Hydroponics, Aeroponics, and LED Grow Lighting. Our basin water is running about 44oC more or less which is what the manufacturer says is what it should be at most. The fan should take it down a fair bit according to what is on greenpinelane. Hopefully that will give a good kick of extra light.

- To eliminate any light contamination cross-over effect for sure, we build a little cabinet around the Led which you can see. We donâ??t grow this way normally so a little concerned about CO2 penetration into the cabinet. We will raise the bottom of the cabinet walls below the pot level. Ideas or thoughts on this one?

- Now I am proud of this one : for the heat around the plant, we have run a coil system from the water coming out of the light around the plants. The idea being to raise up the plant temperature to the same as the HPS so we can eliminate this as a potential difference.

What isnâ??t changing :

We arenâ??t changing our nutrient levels. They stay the same as for the HPS for now. Provided we master the changes above to give us a good baseline test, we will start playing with nutrients in test 3. We have had lots of good suggestions for test 3 nutrient changes. Thanks everyone and looking forward to your feedback.

Weâ??ll post some photos once the plants are in the set-up this week.
ledgrowtester Reviewed by ledgrowtester on . Smartlamp LED grow test Not sure if I am putting this in the right spot but here goes. Hi guys, thereâ??s been a lot of talk about growing with LEDs in the past year and we finally took the plunge after doing a bit of research so I thought Iâ??d share some of our results so far. First, we went with the TI-Smartbar from Theoreme Innovation. After looking into the various lights out there it seemed like they had the best technology and the most powerful lamps compared to all the others some of which looked like Rating: 5