Orchidarium lighting

[clusty]

I am in the process of creating a cold masdevallia tank.
How many t5ho's would suggest for that?
I imagine 4 should give me around 2000FC, which is a good number for masdies.

[naoki]

I would say 4 if you can deal with the heat issue. For Madevallia, you can probably go with 3.

At 1' (30cm), it is probably around 190micromol/m^2/s (1500fc) from my measurement. But this is the standard 4-bulb fixture. If you are spacing them further (which you should), then it is lower. But it is still more than plenty for typical Masdevallia.

If you remove bulbs from a bigger fixture, it doesn't linearly reduce the energy consumption (in other words, you could get really low system-wide efficiency). I don't know well about this, but it is probably something to do with 1 ballast driving a couple bulbs. Better fixtures (e.g. Hydrofarm) have switches to use only a half of the bulbs (then the efficiency shouldn't be affected).

Ray, I think Ron is using 4x T5HO according to the comments there. But he grows plants requiring much more light than Masdevallia.

[Ray]

True enough, Naoki.

However, considering this is supposed to be a "cool" chamber, wouldn't it ne better to go with LEDs?

[naoki]

I agree that a higher-end LED fixture would be better, Ray. But not everyone has enough money to cover the initial cost! I think that clusty already has T5HO, so he might want to use it for now. With cheap LED, it is probably not much better than T5HO (in terms of efficiency, which directly influences the heat generation). Also if the T5HO is outside of the enclosure, heat issue is less problematic (but there will be less light due to dirty glass/plexiglass). If crusty is putting T5HO inside of the enclosure, then I hope his cooling system is good enough. One additional factor is that T5HO output goes down with temperature (opposite of LED).

[clusty]

The lights are outside the box.
In my current setup, with 4 lights outside the box, temperature grows by about 5 deg during the day because of the lights.

For now I use my old T5's. If I cannot manage to keep the temps low enough, I will get some LEDs

---------- Post added at 07:48 PM ---------- Previous post was at 07:47 PM ----------

Originally Posted by naoki

I would say 4 if you can deal with the heat issue. For Madevallia, you can probably go with 3.

At 1' (30cm), it is probably around 190micromol/m^2/s (1500fc) from my measurement. But this is the standard 4-bulb fixture. If you are spacing them further (which you should), then it is lower. But it is still more than plenty for typical Masdevallia.

If you remove bulbs from a bigger fixture, it doesn't linearly reduce the energy consumption (in other words, you could get really low system-wide efficiency). I don't know well about this, but it is probably something to do with 1 ballast driving a couple bulbs. Better fixtures (e.g. Hydrofarm) have switches to use only a half of the bulbs (then the efficiency shouldn't be affected).

Ray, I think Ron is using 4x T5HO according to the comments there. But he grows plants requiring much more light than Masdevallia.

Lights will be at around 30inches.

[Tindomul]

You could always add fans outside the terrarium cooling down your lights. I have a t5 setup over my tank, and it sits in front of AC unit. When the AC is off, temps go up to mid 90's. But if I leave the AC on, with the fan option on, not the cooling mode, then the temps stay below 83. So what I do is that I turn the AC off from 11 am to 4 pm. Temps go up nearly to 90. Then on the AC goes and everything cools to 60 by morning. In the winter time I will have it on fan only. It works great, I get to have my bright lights and low temps too.

[MiniatureOrchids]

Piggy-backing onto this thread, just wondering if anyone has recommendations for LED lighting units. I'm currently at the initial stages of planning an Exo Terra build for miniatures, and starting research into what lights would work for it. Anyone done this?

[clusty]

Are you planning on buying or building your LED lights ?

[MiniatureOrchids]

Buying - I'm not an electrician or EE.

Thinking that (similar to others on this board) putting an acrylic sheet across the top of the ExoTerra would work nicely, and then sitting an LED unit on top (something like Repitsun LED panels) might work well and be simple to set up. Seems that the overlap between reptile kit and orchidarium kit is pretty large.

[clusty]

Decide what you wanna grow so you figure out an approximate foot candle count.
1000lumen/1sq foot = 1000 foot candles

I grow my plants like this:
Phals, Masdevallias ~1000 FC
Cattleya ~ 2000FC