Or_Gro and the epic smackdown

[TEKNIK]

That seems very accurate for a dongle, nice work

[Or_Gro]

Thanks man...could be the broken clock thing, too...accurate twice a day....

[TEKNIK]

I intend to buy a proper spectrometer soon so I can see from 250nm to 850nm. I guess once knowing a true reading then something like a dongle will be fine for the consumer providing accuracy is within 10%. It isn't all that important to have accuracy too high as plants grow pretty fast and so long as you are within a ball park it will be good enough. Once I can determine UVB lifetime then it will be possible to check things with a standard PAR meter providing you count the hours the UVB has been run for. Need to make a graph for this but it should be pretty accurate.
I won't trust manufacturers for lifetime, need to check it myself.

[unkle_psycho]

I was watching that UV overview, and they said that the UV just needs to activate a stress pathway, so even a little is enough, as long as the pathway is activated.

Do you guys think there is a benefit to adding more UV, or is a little enough?

[TEKNIK]

This is something that needs to be worked out I guess, I am sure there is a range of too little or too much that needs to be worked out, also spread needs to be worked out.
Or_Gro with his meters will be able to determine what is working best over a few grows.
I should also be able to provide some input regarding this with my meter once I have a UVB module set up.
10Watts of UVB should be plenty to cover a 4X4, maybe one module powered at 1W each per square foot should do it from what I have read.

[Or_Gro]

First:, when talking UV, it is important to distinguish between the 3 types: A, B, and C.

I’m not sure what the UV Overview says, but i focus on UVB, and intensity & duration matters up to some point, after which the plant gets damaged.

One study along these lines is this one:
https://onlinelibrary.wiley.com/doi/abs ... .tb04757.x

I’ll be running UVB in my 3-way side-by-side at slightly higher level than top end in that study.

[Prawn Connery]

Well Teknik, while I work on my Sensei Master to come across to the dark side, here's a pic of Prawns HighRed Aussie boards on my customised sinks with 2 ft Arcadias for UV. This is 5 days after flip and at about 110 watts per panel laying out 1000ppfd at 12-15inches. I am still learning Dialux and IES files but this setup was measured on a Passport Spectro thingy. I'll see if Prawn will pop in and post the spectrum and some details about his boards.
FC

Hey guys ,late to the party. Here are the spectrographs for Frank's combined High Light 2700K boards plus Arcadia 6% UVB T5 reptile bulbs:

Here is the Arcadia on its own:

And here is Frank's spectrum (green line) compared to the normal High Light 2700K + 6500K UVA boards (pink line):

Obviously the Lighting Passport doesn't go below 380nm, so all the good stuff below that (mostly UVB) doesn't show up. But you get the idea.

[Or_Gro]

Welcome crustacean!

What % is 600nm and higher? The blue looks so small....

I don’t understand how FC’s curve could be below an unsupplemented high light (green below pink)?

[Randomblame]

I was watching that UV overview, and they said that the UV just needs to activate a stress pathway, so even a little is enough, as long as the pathway is activated.

Do you guys think there is a benefit to adding more UV, or is a little enough?

Hey, buddy!
There is a linear increase in thc production with an increased UVB dose. Above a certain dose you'll see damages on the upper leaves. It starts with like heat stress looking symtomes(curled up leaf margins) and later the whole leaves start to roll up. Also the colors change to a more olive looking green and it means your girl has a bad sunburn.
If you keep that level you can really harm the plants. They would quit growing and in the worst case the whole plant can die.

Especially the Agromax pureUV is extremely damaging but also the Solacure bulbs(flowerpower&superb's) can damage the plants cuz they are much stronger compared to reptile bulbs and have almost no visible light.
Reptile bulbs are not that strong and need to run much longer(5x) which means you have a 5x higher power draw with reptile bulbs but it's so much easier to work with them. A 2ft bulb covers a 2x 2' area pretty good. 5-6% bulbs can run all day long, 10-14% bulbs for up to 6h and the bulbs can hang 12-18" above the tops. Special bulbs like the Solacures can be used for up to 2 hours and the Agromax bulb is so strong that you need to keep +24" distance and use it for up to 4x 15min. 1h at noon is already too much even if its the same dose. Really difficult to work with them.

UVB works with the dosage princip which means it usually depends on the total amount UVB per day. I get pretty good results running my 12% reptile bulbs for at least 6h per day.

Unfortunately the site doesn't allow me to upload the according .pdf. If you're interseted visit rui and read the UV threats. I've uploaded the pdf many times..

Ah, and one last thing ...
Start with a low dose 30-60mins the day and keep that level for around a week. It's like with strong sunlight... The plants need to get used to it (in the shade) before they can handle full sunlight.

[Randomblame]

I posted this on the “General” section, but ibet my riu buds haven’t even gone over there yet, so i’m posting in here, jic...



Hey dudes, i have one of these to measure and set height on my uvb tubes:

DF14589C-7875-4E0F-8FDB-AFCF2C44858A.jpeg

It works great, but price is $$$ for some people. So @chiefrunningphist on riu asked me to buy one of these (free app for i-phone/android), and compare to my meter:

CDDA35E0-100A-4EEA-AAA6-0575BC8DC84A.jpeg

Here is one of crp’s posts explaining his rationale:

569A1094-1D01-482B-A1A2-A9DF53FDA642.jpeg

I tested it under a single 4’ tube of these:

85FAEA7A-FE96-4BE5-B336-EF265B5CAE1E.jpeg

I let my light warm up for 15 mins, then ran the meters side-by-side, here’s what i got:

690F8995-F5C7-449B-AE31-3E537969D1E3.jpeg

Line-of-best-fit (plug target uW/sq cm as “x”, tells you target UV Index value):

D38C10EB-1123-4D0F-A4E2-A50D844F1DD3.jpeg

This screenies are showing the test results of an Arcadia 12% bulb with different types of reflectors at different heights. It shows lux, μW/cm² and UV-index measured every 5cm and the other two show how its distributed with and w/o reflector.

Which bulbs have you tested? The 14% bulbs? The UVI meter results are much lower compared to the test results(12% bulb) in this test. 800μW/cm² should be an UVI of 22. A 12% bulb at 350μW/cm² should have an index of 10.

I've ordered the same little meter and I'm curious if I get the same low readings. Perhaps there is a protective film on the sensor that needs to be removed? If not it seems they are not worth is.. Another 25$ in the bin, lol!
Usually the divider is 25 to calculate the UVI, this readings suggest the divider is close to 150.(105:150=0,7). So either there was something wrong or it's simply too far off from a calibrated device.

They have used the same UVB meter like you(Solarmeter 6.2) and the UVI meter was of the same brand. Solarmeters is a very reputable brand and has long time experience in building UV meters and those meters are fully calibrated. So I expect their test results are correct.