Question about T5HO lights - Orchid Board

camille1585 · #1 01-25-2018, 05:18 AM

After deciding that the Ikea led strip may not be a very good led, I've been looking at T5HO fixtures. I have a really dumb question: what makes it high output, the ballast/fixture or the bulbs, or the combination of both? I ask this because a french grow-shop site I found sells a 2 bulb 2ft fixture but without bulbs. When I go to the bulbs section of the site, I find T5 bulbs, but no T5HO specifically.

Alternatively I found another site selling a 1 bulb Sunblaster T5HO , but no replacement bulbs for down the road, leaving me with the same question.

As I search I've very surprised by how little there is in the way of non MH or HPS lighting. Seems like every single site is aimed predominantly at weed growers. I even went to lurk on an EU-UK orchid forum in the under lights section for ideas, and it seems that many people use MH for their orchids, rarely fluorescents...

Paphluvr · #2 01-25-2018, 07:14 AM

It's a combination of both the ballasts and the bulbs. When I was growing under lights many year ago I was using 8' T12HO. As I recall, a normal 8' bulb was 80w vs either 110w or 120w for the HO. Also, the prongs on the ends of the bulbs and the sockets are different between the two. I think this will still be true of the T5's.

Ray · #3 01-25-2018, 07:31 AM

T5 merely designates the nominal diameter of the bulb - 5/12" in this case - and that determines the pin spacing, too. (T12=12/12", T8=8/12", but they have the same pin dimensions, as the T8 is a more efficient retrofit.)

In the standard "four-foot" (actually about 46") bulb, a T5 is a 28 watt lamp, while a T5HO is 54 watts, so puts out a LOT more light.

estación seca · #4 01-25-2018, 04:59 PM

That's interesting about what is available near you. The hydroponics shops here have moved over the years from HPS to T5HO or CFL and now are mainly selling LED. Aquarium shops here carry T5HO replacements but mostly recommend people move to LEDs. Standard fluorescent lights are scheduled to be phased out over some years, but they're still available.

Ray · #5 01-25-2018, 07:36 PM

I'm also curious what made you decide the Ikea LED is no good.

camille1585 · #6 01-26-2018, 02:01 AM

Quote:

Originally Posted by estación seca

That's interesting about what is available near you. The hydroponics shops here have moved over the years from HPS to T5HO or CFL and now are mainly selling LED. Aquarium shops here carry T5HO replacements but mostly recommend people move to LEDs. Standard fluorescent lights are scheduled to be phased out over some years, but they're still available.

The majority of the online hydroponic/ grow shops I've found are mainly selling HPS and the like (as well as massive 200-300W cfls) because it's quite clear their target market is weed growers, who need insane amounts of light. The leds they do have are super large arrays (I need strips for my small shelves) and often those red/blue colored lights. If they have smaller lights Aquarium supply shops carry more T5HO and led strips, but jack up the prices.... I didn't realize that the US was getting ahead of Europe on this!

Quote:

Originally Posted by Ray

I'm also curious what made you decide the Ikea LED is no good.

My main reason was based on my future use of this light. As a supplemental winter light only, the Ikea led would have done the job. However, I would also like to use it in the spring to start some plants for my vegetable garden. The Ikea led has about half the light output of my previous light, which I felt was already borderline for starting tomatoes. A T5HO unit would have given me the light I need, for the same price as the Ikea led strip. (50-60€).

Back to the drawing board!

Subrosa · #7 01-26-2018, 04:21 AM

Quote:

Originally Posted by estación seca

That's interesting about what is available near you. The hydroponics shops here have moved over the years from HPS to T5HO or CFL and now are mainly selling LED. Aquarium shops here carry T5HO replacements but mostly recommend people move to LEDs. Standard fluorescent lights are scheduled to be phased out over some years, but they're still available.

There has been a resurgence in the use of MH lighting by the more serious keepers of sps corals such as Acropora, particularly in Europe. Quite simply they produce better results in both growth and coloration, as long as you deal with the heat produced. 30 years ago a 20,000°K Radium 400W MH bulb was the gold standard for reef keeping. And it still is.