Lighting Chart

[grok]

On 3 hydroponic plants, how many watts of CFL lighting is needed 2 make grow good at least through the veg. stage?

its more relative to the amount of canopy space or square metres of floor space you have to grow with than the number of plants...and your style of growing...SOG style crams 'em in there..anyways check out the grow room calculator thread to help you work out how much light you need.

[Flowerpot]

Light Chart

 

 

 

Jack

 

 

 

 

p.s. this has been edited by stoney and now should work

[Flowerpot]

Thank you - that is exactly what I needed - I will now boost my lighting by getting higher output fluoro tubes.

[jeff lumigrow]

Why do people use old fashion lights when there are cool LEDs on the market that put out the right wavelengths for plants at a third the energy output?

[Reverend]

Why do people use old fashion lights when there are cool LEDs on the market that put out the right wavelengths for plants at a third the energy output?

 

Looking forward to seeing your grow under led's.

[Burnz]

They are pretty cool LED's hey! Would be cool at a party, could hang it from the roof and ya got a strobe light! all the pretty colours n shit..

[The Hash Nibbler]

Did someone say the L word on here? No good shall come of this...............

 

HID will set you free my friend ............................... you will tread the narrow windy path of lesser light , you shall be dissapointed,

you will become one of us ................ansd forever will you and your servants sing praise to the Gods of MH and HPS.

 

Can I get an Amen Brothers.........Let me hear ya ...............Can I get an Amen!!! . Gh72

[whazzup]

footcandles eh ? Did anybody ever hear about micromoles? In professional horticulture we let go of lumens, luxes and footcandles long ago. We measure photon flux, the number of photons in the PAR region (400-700 nm). You need about 8-10 photons to bind one molecule of CO2. Though deep blue photons contain much more energy than far red photons it's not the amount of energy in the photon which drives the photosynthesis, but the photon count.

 

So instead of Lumen we use Photosynthetic Photon Flux (PPF) measured in micromoles/sec, and instead of lux we use Photosynthetic Photon Flux Density (PPFD) in micromoles/m2/sec to determine grow light (not to be mistaken with spectrum for vegetative growth).

 

We measure many different lamps as part of our development and maintenance programs in an Ulbricht integrating sphere. It is impossible to measure the luminous flux of a lamp under a reflector. What you can measure is the illuminance on a certain spot and the uniformity of the light.

[Chato]

Very interesting whazzup

 

I haven't really kept up with the latest trends and terminology regarding lights but the way tech is progressing so rapidly these days it only makes sense there is a whole new way to measure and judge it.

 

Any chance you can break it down a little? Like maybe give some old examples of light ratings using the lumen system compared with the new way to measure them?

 

Do the developments in tech relate to better growing methods? If so, how?

 

Does this render my lux meter obsolete?

 

It all sounds technical and very cool but I an I suppose many members here would be most interested in how it equates to better growing methods?

 

A lot of questions sorry but thanks for the info

 

Peace

c

[whazzup]

I will certainly write more about it, but I'm really very busy at the end of the year, but I promise I'll post some information about it.

 

When you want to measure the uniformity of your light a lux meter is a good instrument, after all you are not after absolute figures but you are comparing levels. A lux meter gives you a good indication but it doesn't say a lot about the luminous flux of the lamp when you measure it under a reflector. To compare levels it is good enough. I will post some test data which shows a measurement of two lamps on the same ballast, one clearly outperforms the other in lumens, but has a lower PPF in micromoles. I think scientist agree that Micromoles is the way to go these days. The Wageningen University has a lot of research papers about the subject.

 

For those who wonder what an ulbricht sphere is:

 

This is the test roon, with the sphere on the right and the measurement equipment on the left. Behind the sphere you see the tridionic reference ballasts. All input and output signals are measured with a high frequency power analyzer: That way we can see how much power a ballast uses, but also for example how much is actually sent to the lamp (and at which frequency and wave form). The sphere and the measurement equipment is calibrated with a standardized measuring bulb.

 

The lamp is free hanging in the middle of the sphere, for a measurement is is closed of course

 

We also check the arc tubes for acoustic resonance. You can do that yourself too, use welders goggles and don't burn yourself!

 

The arc should be stable and without bumps and knot. Here is an

 

But which bulb on which ballast is another topic