HID vs. T5HO in my growing area

[jkt97401]

Hello all,

I need a grow light. I don't know which would be best for my situation so any help is appreciated.

I will be hanging these in a space under my basement stairs, however, the distance from the "ceiling" is about 4-5 feet, I don't know if HID lights need to be further than that but take into account that some of the HID lights I've been looking at can ramp power back to 75% or 50% if needed. I could also look into cooling. I also don't know what wattage I should get, I've been looking at 400w and 600w. The temperature is currently maintained around 75-78 during the day and about 10 degrees less at night. I'm not sure if humidity will play a role but I have between 60-70% RH. I kinda like the idea of HID because I want to eventually look into Vandas! I currently have mostly Phals with some oncids.

Thank you all for looking!

[WhiteRabbit]

[jkt97401]

Bump indeed! Haha

[Leafmite]

You can buy these little 'pully-type' things to lower and raise your lights. So, you could buy the T5HO and just attach those to the lights and then lower them. I bought a set and could not use them as I have my lights on shelves and needed all the space I could (I had to use S-hooks to attach my lights).
I am using the T5's for the first time and I admit, I really love them.

---------- Post added at 07:46 PM ---------- Previous post was at 07:43 PM ----------

You can also buy some chain to put the lights at the right height.
I did quite a bit of research and decided that the T5's were the best option for me. I went with the Hydrofarm Envirogro (I think that is the way they spell it) 4ft, 4bulb fixtures.

[jkt97401]

Thanks Leafmite! Will those T5HO lights be strong enough for Vandas? I have heard a few people say that they've had success but I'm curious about HID because I would have a large grow area hehe.

[Leafmite]

I think that they are if you are indicating the 'strap-leaf' type of Vanda. You might just need to leave them on for longer hours.
The more light your plants need, the closer you need to have the lights to the plants. That is why they sell those things that you can use to raise and lower your lights. When growing things like tomatoes indoors, you can slowly raise the lights as the plants grow so they can continue to get the high light they need. And, yes, if you can grow tomatoes and miniature roses under the T5H0 lights so you should be able to bloom strap-leaf Vandas.
Good luck!

[Joseia]

I grow under lights and use both an HID and T5HO set of lights. The HID is a 600w adjustable HPS ballast with a 600w Plantmax MH conversion bulb. It puts out a lot of heat, and if the space is small and enclosed, you will probably need some ventilation. The heat works for me because I get about a 12 degree drop in temperature when the lights go off at night. The T5HOs get hot, but not nearly as hot as the MH. If you are spraying water in your grow space and have an HID light, you will need to make sure water does not get on the hot bulb or it will explode.

About the humidity - an HID runs very hot and does a very good job of drying out the air in my grow space.

[Leafmite]

They explode? I am relieved that I went with the T5's, then.

[jkt97401]

I have a humidifier and I don't like spraying water unless it's directly into LECA to keep the top moist. I also don't mind ventilating, air flow is good! like the idea of an HID setup because of the large grow space I can get!

Joseia, what kinds of orchids are under your HID? Do you switch back and forth between MH and HPS? If so, when and why?

[Joseia]

Originally Posted by Leafmite

They explode? I am relieved that I went with the T5's, then.

Oh yeah, they blow up nicely if water gets on the really hot bulb. A glass covered reflector is a good idea. The MH bulb actually has two sets of glass bulbs, an inner and outer set. If the outer set is cracked, the inner bulb may still light, and if that happens, you can cook your plants within a few hours with UV radiation, and it can hurt you too.

---------- Post added at 10:27 AM ---------- Previous post was at 10:11 AM ----------

Originally Posted by jkt97401

I have a humidifier and I don't like spraying water unless it's directly into LECA to keep the top moist. I also don't mind ventilating, air flow is good! like the idea of an HID setup because of the large grow space I can get!

Joseia, what kinds of orchids are under your HID? Do you switch back and forth between MH and HPS? If so, when and why?

Yes, with the HID you can cover a wide area, with plants that require lower light along the edges of the lit area and those that require more light closer to the center. One thing about the HID light: it is a point source of light, just one bulb, so plants along the edges of the light field will bend towards the light. That is less of an issue with the longer T5HOs.

I use the T5HOs for my phals, African Violets and Tillandsias. Under the MH light I grow mini vandaceous (Neostylis, Ascofinetias, etc), Brassavola and Dendrobiums.

The hardest thing I have found about growing under lights is figuring out how much light to give the plants. Most foot candle data is based on growing outdoors in natural light. So when I read that a plant needed 2000 fc to bloom, I cranked up the wattage and very quickly cooked them. My rule of thumb for fc under the MH is to divide the recommended fc by at least half. You really need to observe the color of the plant themselves for cues about too much or too little light.