Lighting Any cob users measure lux at canopy?

[Animatey]

Been a while since I've run hydro, but that temp made me go !

For real... Basically I switched out a pump that was recirculating my rez and the new pump was generating lots of heat...

Put the old pump back and temps plummeted...

I'm doing TFR so rez temps aren't as big of a deal compared to DWC, like it's much harder to get root disease, but it's still important (apparently) and I made the same face when I took a temp reading.

Here is the setup, still working out the kinks, but it's pretty straightforward. Like a water farm , but with a 10 gallon rez:

Bottom left side is the drain back into the rez

 

[Arthur]

Very clean. Basically a stand alone drip/flood?

 

[MesaBoogie]

It would be cool if we could get @BigSm0 to send one of his Cobs to Migrow to test. We could see how his lights stack up to other cobs and benefit from a par map as well. I think it would really push the popularity of his light.

 

[Animatey]

It would be cool if we could get @BigSm0 to send one of his Cobs to Migrow to test. We could see how his lights stack up to other cobs and benefit from a par map as well. I think it would really push the popularity of his light.

I'd be interested in just a lux reading with a lux meter in a successful grow. The light from cobs is white, so it's not a bad way to measure them. In my photo grows I would use a lux meter with my cobs and know it could be a little lower than HPS lux numbers and be good. Good HID lux ranges and cobs Lux ranges are not that far from each other IMO.

 

[Animatey]

Very clean. Basically a stand alone drip/flood?

Yessir, 10 gallon rez with 1 gallon hydroton for the root space. Sort of experimental... Working good so far though! There was a user on this site that was active for a while, did about 4 years perpetual and journaled it all out. 1 rez, 1 plant in about a gallon of hydroton in a very small space with great results:

https://www.autoflower.org/threads/ksja-s-perpetual-micro-hydro.46810/

That's what inspired me to try it and I got a lot of info from him on how he was doing it. So far it's my favorite way of doing active hydro. Real low maintenance and easy to do the maintenance.

 

[LazyNhazy]

I run 20k lux on top canopy for veg and 40k on flower top canopy with no issues other than wanting more nutes. Makes fatter more dense buds also.

But more light is always going to mean more nutrient uptake. Only to a point though then you need Co 2

 

[Animatey]

I run 20k lux on top canopy for veg and 40k on flower top canopy with no issues other than wanting more nutes. Makes fatter more dense buds also.

But more light is always going to mean more nutrient uptake. Only to a point though then you need Co 2

Awesome thanks for the numbers!

What color temp are your cobs? 3500k?

 

[LazyNhazy]

Awesome thanks for the numbers!

What color temp are your cobs? 3500k?

6500k

 

[Animatey]

6500k

Even in flower? Seems pretty blue but I've heard people have good results with blue color temps in flower.

 

[Mañ'O'Green]

Looks similar, but it's just started so it almost looks like Mg def. Also the serrated leaf edges are slightly curled and burned looking almost like heat stress.

I thought it was Mg def except none of the lower growth had the issue so eventually after a full day of troubleshooting, some ppl here helped me figure out it was light stress.

I think the big issue was that I lost control of my rez temps and they were at 77f...

My guess is that drinking hot water was giving her trouble with the light (and probably other things).

Rez temps are back to 70f and I'm raising the light intensity by 1-2k lux a day and she seems ok now. pH is stable again and so is EC which were both previously requiring me to make twice daily adjustments.

I'm not sure how high I can go with the lux but I'll try to update here as she goes into full flower over the next few weeks.

Thanks for posting some info here on your heights etc. Good knowledge for cob users!

PS here is a pic from a few days ago
View attachment 1137364

Only on the upper most leaves closest to the light

That looks like a Potassium Deficiency to me.
Ps. Too much Potassium looks the same!