UV light or photoinhibition

[ArcticOrange]

Heres a scientific study so everyone can stop saying theres no evidence or its all anecdotal.

 

[ArcticOrange]

I dont think too much light has the same effect, id stick with 5-10% uv light and grow as normal my .02.

 

[BobCajun]

I dont think too much light has the same effect, id stick with 5-10% uv light and grow as normal my .02.

I'd like to see an experiment to see how close reptile CFLs need to be to make a significant difference.

 

[ArcticOrange]

I keep mine 6 inches away, ive noticed the difference, you can feel them on your skin, itll sunburn you lol

 

[ArcticOrange]

 

[BobCajun]

View attachment 3619430

I put a couple 13w uvb 5s in a cab grow but I mounted them up at the top so probably 18" away. I guess they really need to be about 8" away at most.

What if reptile lights were cheap and you just put about 20 26w UVB-5 bulbs in a 3'x3' area as the actual grow lights? I bet you'd get some potent stuff then. As prices are now though, it would cost you about $600.

 

[ArcticOrange]

I dont think they have enough PAR light spectrum to be used alone.i shoot for the higher end of avg on earth. Mimic high altitudes where the most potent natural strains have been found.

 

[Greenthumbs21]

I'd like to see an experiment to see how close reptile CFLs need to be to make a significant difference.

Well to give you an idea.. i have let them touch a leaf over night and they didnt burn it.. and the box said its not effective for lizzards after like 13 inches so.... anywhere in between is good

 

[~CReePeR~]

How should UVB be run during a grow, 1) from start to harvest 2) from start of flower cycle to harvest or 3) 2-4 weeks into flower cycle (depending on length of cycle) to harvest?

 

[BobCajun]

How should UVB be run during a grow, 1) from start to harvest 2) from start of flower cycle to harvest or 3) 2-4 weeks into flower cycle (depending on length of cycle) to harvest?

This Dutchman guy did some experiments with UV and said you only need it the last 2 weeks. In fact he said he got down as low as 1 week and it still worked but he recommends 2. I guess he uses long fluorescents.

 

[~CReePeR~]

Thank BobCajun, I figured it was a short time.

 

[Greenthumbs21]

How should UVB be run during a grow, 1) from start to harvest 2) from start of flower cycle to harvest or 3) 2-4 weeks into flower cycle (depending on length of cycle) to harvest?

Well in order to mimic an outdoor flower cycle its used throughout... i add them right after stretch is done about week 2 till chop. The last 2 weeks is good for maturing trichs already there but they help in the early stages building protection too.

 

[~CReePeR~]

Wow, looks like a worth wile experiment to try

 

[qwizoking]

It should be used throughout

 

[rkymtnman]

I'd like to see an experiment to see how close reptile CFLs need to be to make a significant difference.

i have 23 watters 15.0 and their effective range is up to 20 inches

 

[rkymtnman]

Well in order to mimic an outdoor flower cycle its used throughout... i add them right after stretch is done about week 2 till chop. The last 2 weeks is good for maturing trichs already there but they help in the early stages building protection too.View attachment 3620245

i do the same. after stretch until chop

 

[BobCajun]

I haven't found much if any difference with the rep bulbs, though they are about 18" away so maybe they need to be quite close. The problem there is that they would block some of the main light. Now I'm trying using the UV-B for a week and then stopping using them for the last week. Maybe they will then put out more resin to get ready in case they get dosed again.

 

[rkymtnman]

I haven't found much if any difference with the rep bulbs, though they are about 18" away so maybe they need to be quite close. The problem there is that they would block some of the main light. Now I'm trying using the UV-B for a week and then stopping using them for the last week. Maybe they will then put out more resin to get ready in case they get dosed again.

i used to run the uv for basically the whole 12 hrs. i'm trying on this grow to do it just from 10 am to 2pm to mimic the higher uv during the sunniest part of the day. we'll see how it works.

 

[BobCajun]

i used to run the uv for basically the whole 12 hrs. i'm trying on this grow to do it just from 10 am to 2pm to mimic the higher uv during the sunniest part of the day. we'll see how it works.

I read an article where they only used UV for an hour at lights on and an hour before lights off and it worked. Could probably use them for an hour before dark only.

 

[Greenthumbs21]

I haven't found much if any difference with the rep bulbs, though they are about 18" away so maybe they need to be quite close. The problem there is that they would block some of the main light. Now I'm trying using the UV-B for a week and then stopping using them for the last week. Maybe they will then put out more resin to get ready in case they get dosed again.

Thats your problem. ... keep them within a foot... i keep them at 6 inches and move them around