T5 HO-about to give up on her!

Discussion in 'Lighting' started by Student0420, Mar 29, 2012.

  1. 2 months ago I purchased a T5 HO to vegg my plants with. It became obvious very fast that the light was to powerful to use on starts or younger plants because it fried them immediately. Also, put the Temp in my growroom/closet to over 90f. I increased airflow to unreasonable amounts with absolutely no luck at all.
    I gave up on the light and went back to all LED's, but just recently am trying again. I increased airflow (again) and raised the T5 to 18" above the plants. It hasn't fried the plants (yet), but once again the small(er) area heated up to over 90f and the plants start to look wilted.
    My best guess is that the panda plasic...well, I have no good guess anymore. I'm about to take this light out and shoot it!!
  2. They have air cooled t5s
  3. t5's are fine to use on seedlings, clones, small plants, big plants, w/e.

    You must be doing something else wrong, 18" away is waaaaaay to far, they should be within inches of the light so they don't stretch.
  4. Use a couple of cfl's until the plants are big enough, but this is a very rare complaint, T5's run coool!!!! thats why we use them, go checkout those lights, maybe bad wiring???

  5. I think I got a grip on it. Airflow that is sufficient for LED's is not sufficient for T5's. This 4'/4 light HO T5 does produce way more heat the any LED I have used to date. Because I use CO2, and was using only LED's, air in and out has been kept to a minimum so the CO2 level could build up. Temp was never an issue...till the T5. Anyways, increased fresh air in and out and temp is staying steady. Thinking of hooking the CO2 to the air-intake...
  6. Owe ya, using the T5 HO, supplemented by 3 glowpannel(14W) for sidelighting for my flowering area. We will see how it works(-:.
  7. #7 Hank Alvarez, Apr 3, 2012
    Last edited by a moderator: Apr 3, 2012
    Student: Ouch! That hurt because I'm a true believer. T-5's operate at cooler temperatures than other lighting options but you still have to be careful. If you decide to give them another chance use the "back of the hand rule," next time for distancing your lights to your plants.

    First of all your in room ambient temperature has to be within a range of 65 to 80. Over that you'll likely have problems.

    Lower your lights to a couple of inches over the tops of your plants and put your hand over the tops of your plants, palm down. If the back of your hand feels hot raise the lights.

    Don't forget vegging plants can grow 1" to 2" a day so you're going to have to recheck your lamp spacing at least a couple of times a day.

    The manufacturer of my T-5's recommends 6" to a 1' distance but I found a couple of inches to be more effective for stimulating vegetative growth if you stay on top of it. And you need to remember to keep a fan going all the time your lights are on. It's not so much that the lamps burning your plants as the lamps heating the air below them and above your plants and the air overheating your plants. Keep this in mind next time and you shouldn't have a problem. I hope this helps. Hank
  8. Are you pulling cooler air in down low and venting the hot air out up high to a different area then where the cooler air is being pulled in from?
  9. There's the dilema you face no matter the type of light apart from LEDs. With CO2 you've got to keep air circ to a minimum. Most are forced to employ an air cond. with CO2 for this very reason. I'm at odds with CO2 use anyway. While some swear by it, I've also heard many veteran growers insist it isn't worth the cost and trouble. Because CO2 is heavier that ambient air, unless you have a small dia. PVC or vinly tube perforated distribution header suspended with adjustable rigging just above the plant tops it doesn't work effectively because the CO2 hangs near the floor and doesn't benefit growth as much as some hope. The room has to be avoided, distribution is a hassle and growth rate isn't that much better overall. Just my 2 cents.

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