a step beyond T5's .....I found T4's

[calbunn]

Originally Posted by johnblagg

to be dimmable you have to have a ballast that supports that I think and I dont have any need to dim grow lights ...lol if I need less light I turn some off or use smaller wattage lights

Me too but I have a greenhouse application I'm trying to maintain a 18mole count per day on with a combination of sunlight and supplemental HID or fluorescent possibly.

[johnblagg]

Originally Posted by calbunn

Me too but I have a greenhouse application I'm trying to maintain a 18mole count per day on with a combination of sunlight and supplemental HID or fluorescent possibly.

well you could certinly buy a dimmable ballast and use these bulbs but I dont have a clue how you would hook up a dimmable ballast.

[johnblagg]

Originally Posted by silken

So you don't replace them after 12 months? I thought these ones too should be replaced even if they aren't burnt out.

actually they always recomend replacing them at 12 months but I have never been very worried on that count either .....they do drop in output but even with a lower output will work.Now if you were growing in a production setting yes it would matter.

The cfl twisty bulbs in the back are over a year old and going and the orchids dont seem to notice ....

[Jayfar]

Originally Posted by johnblagg

Ok this is how I built the first sets and mounted them ...no reflectors at all since its a dedicated room and flat white walls.

I think the orchids are happy under them .....

Simple pvc pipe fittings and pure silicone caulk to glue every thing together

I remove the plastic base of the lights that have the pins and solder new wire leads to which I run the wireing from the ballast not that hard to do ...I did run the wires through the pvc on the top arms

There is 130 watts on each arm...and they are 12 inches above the plants

Hmm, I've seen these at HD too and was intrigued, but couldn't find a fixture to go with them other than construction work lights and outdoor flood fixtures. It didn't occur to me to make my own fixtures. I'd love to find compatible sockets for these to eliminate the soldering. What specific ballast do you use?

The next logical step would be to rig some sort of reflectors above these to utilize the light that other wise is wasted on your ceiling.

[johnblagg]

Originally Posted by Jayfar

Hmm, I've seen these at HD too and was intrigued, but couldn't find a fixture to go with them other than construction work lights and outdoor flood fixtures. It didn't occur to me to make my own fixtures. I'd love to find compatible sockets for these to eliminate the soldering. What specific ballast do you use?

The next logical step would be to rig some sort of reflectors above these to utilize the light that other wise is wasted on your ceiling.

Ge multi-volt pro High preformance electronic ballast

GE296HO-MV-N-DIY is the number on the ballast

and lol the light that get reflected off the ceiling is reflected onto my lower light plants that sit in the floor nothing is realy wasted in such a small room now what gets out the windows that is wasted and lol Im sure annoys the next door neighbor



Here is what the light that reflects from the celing does....

[Merlyn]

Dimming as an eco friendly or financial savings option is an oxymoron created by greedy marketing !!! A dimmer is NOT like a water faucet where you turn the handle and the water flow slows down. When you turn the handle on a dimmer and it dims your 100 watt light to 50, you put the other 50 watts on your dimmer and it comes out as heat !!! No matter what THEY say, you keep it dimmed to 50 watts for an hour and you WILL get charged for a 100 watt hour !!!! You CAN'T reduce the 110 volts with a dimmer !! If you know OHM's law E=I x R and P=I x E you know what I mean. There is NO SAVINGS, except for light bulb life, when using a dimmer !!!! The rest is simply marketing BULLS**T masquerading as eco-friendly !!!! The same BS also applies to the CFL bulbs being eco-friendly when they contain mercury just like all the other florescent tube types do !!!

[calbunn]

Originally Posted by Merlyn

Dimming as an eco friendly or financial savings option is an oxymoron created by greedy marketing !!! A dimmer is NOT like a water faucet where you turn the handle and the water flow slows down. When you turn the handle on a dimmer and it dims your 100 watt light to 50, you put the other 50 watts on your dimmer and it comes out as heat !!! No matter what THEY say, you keep it dimmed to 50 watts for an hour and you WILL get charged for a 100 watt hour !!!! You CAN'T reduce the 110 volts with a dimmer !! If you know OHM's law E=I x R and P=I x E you know what I mean. There is NO SAVINGS, except for light bulb life, when using a dimmer !!!! The rest is simply marketing BULLS**T masquerading as eco-friendly !!!! The same BS also applies to the CFL bulbs being eco-friendly when they contain mercury just like all the other florescent tube types do !!!

I believe the older style slide and rotary dimmers would have the heat issues but I use digital ballasts for my HID lamps for indoor plants and I would like to explore using them as supplemental in our greenhouse for when it's cloudy.

With the digital ballast I can switch between 1000, 750 or 600 watt settings and the KW meter I use clearly indicates a corresponding reduction in watts consumed.

There is no difference in heat coming off the ballast regardless of the setting so the savings is there. But i want to not over light my plants and I want the light levels adjusting automatically to compensate for available sunlight. Not only does that represent an energy savings but I can accurately manage the photosynthetic absorption on a daily basis.

What type of lighting are you using if any?

[camille1585]

Originally Posted by silken

So you don't replace them after 12 months? I thought these ones too should be replaced even if they aren't burnt out.

I should have, but never got around to stopping by the terrarium supply shop not far from me to get more. It's a 45min bike ride over, so I need the motivation to go!! But since I'm not exactly sure how these age, I'd like to get a lightmeter at the same time I put in new bulbs so I can monitor their output over time.

[johnblagg]

With the digital ballast I can switch between 1000, 750 or 600 watt settings and the KW meter I use clearly indicates a corresponding reduction in watts consumed.

There is no difference in heat coming off the ballast regardless of the setting so the savings is there

ok if there is no difference in heat at the ballast then the savings is not at the ballast end .....use a light meter and check light levels the output at the bulbs has to be what changes ....

since I have never had a digital ballast I dont know anything about them realy .....as for over or under lighting your plants ....when you switch wattages when using hid lights you have to lower or raise the lights a corresponding amount or you will still be under or overlighting ...600 watts of hid needs placed closer and jumping from 600 or 750 to 1000 at that placement is going to be a disaster

[Ray]

There is a lot to consider when acquiring artificial lighting.

Stefano - the color temperature tells you what the spectrum is like. something ion the 6400-6500°K range is supposed to most-closely match that of full sun with blue sky back-scatter, and the absorption spectrum of the chlorophylls and related carotenoids that pump energy into them.

Also, if appearance of your plants is of importance to you, you have to think about the color rendition index - CRI - which is supposed to be a rating of how it compares to sunlight (CRI=100). John's bulbs have a CRI of 80, as being designed for outdoor lighting, it's not that important (although his plants and flowers still look pretty good). Most fluorescent fixtures intended for plants will have higher indices. Plants grown under many LED light fixtures containing red and blue LEDs too downright alien.

How large of an area the light can effectively illuminate is determined by the bulb's designed output, it's geometric layout (CFL's lose a lot to the interior of the spiral, for example), and very importantly, the reflector. In John's example setup, he's not using half of what he's got available!