PiffinOut said:

So correct me if I am WRONG. Cobs are less efficient than QB.
But are QBs more efficient than strips.
How do XPE and XM stars rate in terms of efficiency?
Sorry to ask on her but I am having a hard time finding information regarding this. Perhaps there a specific series/sequence/terminology of words I should be looking for to get actual results in furure

Click to expand...

So efficacy has a few different places.

1. The efficacy of the fixture to turn watts into light energy... this is not only related to Quality of the components but also the spectrum. Red I believe is the most efficient in this aspect but a balanced spectrum is needed.

2. The efficacy of the plant to absorb that spectrum... blue and red being most efficient but again all are needed.

3. Efficacy of the fixture to get the most photons to the plant without losing them to light bleed or filtering. Meaning first off any lenses or glass may reduce the the number of photons that make it to the canopy but in some cases help more than hurt if it reduces the light bleed more than what's lost from the lens.

Now the angle of lenses plays a huge role in this. Something like a strip light with wide angles and very spread out diodes will loose a lot more light at say 4 feet above the canopy than say a cob with a narrower angle lense at that height.

To put it short and simple a strip light can be put very close to the canopy reducing the light bleed a lot and getting almost all the light produced to the canopy.

A cob since the diodes are so close requires more distance and a lens in order to get even speed with no hot spots reducing the ability to eliminate bleed and the extra lens reduces that a bit further.


QBs while diodes are more spread than cobs are less spread out than strips and will also need to be a bit further to get even spread with no hot spots although the don't need a lense so I'd say in improvement from cobs.

Strips can be very close as the diodes are spread out even more than QBs and require the least distance for even spread. This reduces light bleed a lot and imo gets the most of the photons produced to the canopy and relies much less on reflective surfaces.

Plain and simple they all work well when used properly. Often your grow space height will dictate which ones are ideal. When used properly to get even coverage the amount of light loss is not usually a major factor as we tend to ensure our fixtures are capable of the intensity needed but if splitting hairs the strips win