I am flowering now with Mars hydro LED and a generic LED panel, I added some t-5 high output desert UVB lamps, 22 inches, two of them. I had them about 14 inches from plants during the 12 hour light on period. It started to fry them so I turned it off, flushed and added fresh water. They all recovered except 1. My question is do you use UVB during flowering to induce high crystal/trichome production. If so how far away from plant tops and how many hours in a day with lights on? Also I had several old 48 inch t-12 flourescent tubes and put them about 6 inches away from sides of plants )replaced bulbs with 6,500 Kelvin. They started to get wilty, how far should they be from sides?
careful with the UV-B intensity, without proper ratios of UV-A and UV-C. it would take me an hour to explain but suffice to say that light is not what you're looking for in a plant grow light. if you have to use it, make it for maybe 2-3 hours at most in the middle of your time allotment but seriously it's not a good choice for plant growth. better would just be to add flouro's in the 5-6k range.
Using a 10k(color) mh bulb the last two weeks is said to help harden off the flowers and make the oils produce as much as possible. I've been running into this more and more here lately. Whereas 6500mh is good to veg with and 2600hps is good for flowering try pulling the hps at 2 weeks to go and running the 10,000mh to the finish. Also, I like the idea of vertical side lighting but be sure your clearances and air flow are sufficient. Anyone remember the phototron that high times has been selling forever? Excellent design! Sent from my iPhone using Grasscity Forum
Ok here is the output spectrum 10% UVB output, 30% UVA output it states effective up to 20 inches from lizard dont laugh at my grow room, had to rig up lighting and reflector material. When I first got it I had several plants that were in last few weeks flowering and after the first day of using it crystals coated everything. I was very surprised. Used for a week for the full 12 hours lights on. I harvested and kept it on plants that were in beginning stages of flowering and thats when it fried them. So lesson learned, only in late stages flowering and only for limited time. I noticed several LED light manufacturers are now starting to add UVB tubes for late flowering stages. I come across growers using UVB but when to start using them and for how long and distance of UVB light to plants is all over the board. I have never used t-12's for growing but everything i read is they should be as close as possible, just a few inches from plants but when I did that it started to wilt, had to pull the side lighting tubes about 12 inches away.
Yea I have read that about MH bulbs but I cant use them because of the heat. Phototron still being sold today How far would you suggest having the side fluorescents away from plants?
a 3-1 UV-A to UV-B ratio is good and should be fine. I don't laugh at anyone's grow room amigo and in fact appreciate the ingenuity more than anything else. Anytime you can include as close to full spectrum as possible will benefit plants in all stages of growth so yeah adding some blue to flowering is good and even better when you run it right through the entire grow. There are certain physiological process that plants need to do that require blue light, can they get by without it?, sure. Can we get by without a leg?, sure.... As for how close to run them, they should be fine at whatever distance you like that doesn't bleach or over heat them, like any other bulb really.
The addition of UVB lights was only to cause the plant to make lots more Trichomes and according to some they say can increase potency 5-10 %
I've seen vertical requirements at 12-15". If your light is UVA UVB heavy they recommend slighting your hours by a couple per every 24. Sent from Skylab
Thanks, The side lighting is just 6,500 k 4 ft tubes The UVB light I am using two HO t-5 22 inch, I had them about 12 inches from canopy and had them on full 12 hours I backed it up to 21 inches and cut time down to about 6 hours on and by 2nd day crystals everywhere...I scoured several forums on growers using UVB and distances and do's and don'ts but couldn't find hardly anything. I will snap some pictures tomorrow.
Hortilux is coming out with some real nice flouros. I've always wanted to supplement my dark corners with some good light so that I wouldn't have to lollipop my plants quite as aggressively as I normally do. There's some really cool stuff coming to market. Let the dust settle so the prices come down a little of course. I think we could run either verticals in the corners or parallel to the floor with the daisy chain fixtures around the entire perimeter about a third of the way up on the canopy. Sent from Skylab
jpete, There is no set distance for any light source, just general guidelines really and it has to be that way since bulbs change over time. You should be able to run those bulbs within 6 inches of those plants without issue since the total lumen output from 22 inch florescent bulbs is low, (color temperature matters not). I run those 24inch bulbs in a closet for my male flowers some times and I run them 8 inches above without issue. And technically your bulbs should be referred to as UV bulbs and not UVB especially since they are more UVA than anything else. True germicidal UV bulbs run mostly in the UVC range which is detrimental to living organisms in certain amounts. UV-A plants love, UV-B they enjoy in small doses, UV-C they tolerate at lower doses but too high and you have degradation of plant tissue. HTH
View attachment 7029 I think some may have misunderstood me, the 4ft tubes are the side lighting, plain 6,500 k t-12's. The UVB lights i was speaking of are really UVB lights. Zoomed reptisun found here http://petco.com/product/122972/Zoo-Med-ReptiSun-100-UVB-T5-HO-Lamp.aspx?CoreCat=OnSiteSearch I figured out the distance on t-12's plain fluorescents but wanted some input on UVB lights. The output spectrum 10% UVB output, 30% UVA they are only used the last four weeks of flowering. Many LED manufacturers are adding true UVB lighting as it forces the plant to make tons of Trichomes to protect itself. Here is one http://hydrobuilder.com/new-solarstorm-880w-led-grow-light-with-uvb.html I was hoping to get some people that uses UVB in late flowering their input and some basic do's and donts. My main grow lights are Mars hydro reflector series and a generic LED (smaller unit) pictures will show 4ft side lighting and the 22 inch dual UVB high output t-5 View attachment 7029
I use full spectrum through the entire grow and my Hortilux blue bulbs are putting out quite a bit more UV then your reptile lights I assure you of that and I have no issues with my plants. Plants evolved under full spectrum lighting for tens of thousands of years, that's about it really. Only way to figure it out is to try it and see how it goes. HTH
Solis Tek is really paying close attention to the glass they use for their bulbs so that little to no UVA or B is depredated from using poor quality glass. Sent from Skylab
Yeah I like their bulb spectrum's and I'm currently testing one to see how well they are with lumen maintenance.
Hortilux has a nice 54 watt T-5 bulb coming out that I'd like to use for my supplement lighting in flwr space. Power Veg http://www.eyehortilux.com/products/power-veg.aspx Right now they're only available in 4' Sent from Skylab
That's a decent flouro there, I use their 400 MH blue bulb and am enjoying what I'm seeing but again lumen maintenance will decide for me.