Minimu Lux Needed

[jimlau]

i'm setting up indoor grow lights for my ficuses. is 1,000 lux reaching the foliage enough to make a difference?

thanks.

 

[Poink88]

Not sure but my set-up using regular 6500K T8 bulbs are rated at around 2,900 lux per tube. I use two tube fixture and by the time it is spring, my plants are alive but "limping". I believe they need a lot more.

 

[jimlau]

Not sure but my set-up using regular 6500K T8 bulbs are rated at around 2,900 lux per tube. I use two tube fixture and by the time it is spring, my plants are alive but "limping". I believe they need a lot more.

but how much of that light is reaching the foliage?

 

[Poink88]

but how much of that light is reaching the foliage?

Not sure but they are just several inches from the top.

 

[GrimLore]

I was under the impression Lux is hard to calculate as it is based on the reflection of the surface being exposed to the light... That being said I don't see any reason why what others use should not work. It would suggest however that a reflective setting such as Silver Mylar interior sides and back would help a lot...

Grimmy

 

[Poink88]

I was under the impression Lux is hard to calculate as it is based on the reflection of the surface being exposed to the light...

You're right. I meant lumens.

 

[GrimLore]

You're right. I meant lumens.

Yes and therefore I do not understand the original question. Not being a smart ass but there is no real way to answer it IMO. Either way I think what you have should work fine and perhaps you just need some reflective material or higher/lower humidity. For our tropicals I use some awful inexpensive 75w "grow lights" 24 inch that consume 17 watts. The humidity is between 50-70 percent depending on time of day and lights being on/off. They produce little or no heat really and everything stays at 68-70f same as the room. Each light takes care of 3-5 plants and works out just fine. The Tropicals are surrounded by clear shower curtain material. I use the same lights for Succulents, Cacti, and Desert Rose and no enclosure. They all get 16 hours of light on a timer and it quite simply works. At the new place we are adding some and on the 2 new lights I am adding reflective as they will be packed into to two areas.

Grimmy

 

[jimlau]

Yes and therefore I do not understand the original question. Not being a smart ass but there is no real way to answer it IMO. Either way I think what you have should work fine and perhaps you just need some reflective material or higher/lower humidity. For our tropicals I use some awful inexpensive 75w "grow lights" 24 inch that consume 17 watts. The humidity is between 50-70 percent depending on time of day and lights being on/off. They produce little or no heat really and everything stays at 68-70f same as the room. Each light takes care of 3-5 plants and works out just fine. The Tropicals are surrounded by clear shower curtain material. I use the same lights for Succulents, Cacti, and Desert Rose and no enclosure. They all get 16 hours of light on a timer and it quite simply works. At the new place we are adding some and on the 2 new lights I am adding reflective as they will be packed into to two areas.

Grimmy

I will be upgrading my lights to several >100 watt cfl's. they put out about 9000 lumens each.

I have a lux meter, and what I have seen is lux is what to measure, as lumens is the total coming out of the bulb, not what the foliage receives. obviously if u have reflection all around most of it hits the foliage.

anyway, I thought 1000-2000 lux is the minimum u want, but preferably double that.

interesting light through the window here is about 2500 lux (top of my scale). when cloudy, it's maybe <200 lux, essentially worthless I think.

 

[Poink88]

Have you taken measurements outside in; full sun, overcast, shade, etc? That should help you.

 

[GrimLore]

Have you taken measurements outside in; full sun, overcast, shade, etc? That should help you.

You my dear friend are typing and not reading If he tests outside in this area today he would be simulating a 50f day and at close to 3pm it looks like 7pm here in Winter(dark).

We he did state though was helpful and I am pretty certain his 2000 goal will be more then adequate. He is trying to simply keep tropicals alive for our rather cold winter. If he has that amount of light and decent heat his plants will do well as I stated earlier the temperature and humidity is as important as the light. I think his light goal is realistic and should work out well.

Grimmy

 

[Poink88]

You my dear friend are typing and not reading

Not really. I believe in getting readings (esp if you have the meter anyway). I have plants all around my yard and they get different light intensity exposure. I can get a reading where I think it is optimal or at least where they are not deteriorating and use that as a benchmark. FYI, in my covered patio, there is an area where the plants are alive but not thriving. Reading from there will help as well. Wrong reasoning?

 

[GrimLore]

Not really. I believe in getting readings (esp if you have the meter anyway). I have plants all around my yard and they get different light intensity exposure. I can get a reading where I think it is optimal or at least where they are not deteriorating and use that as a benchmark. FYI, in my covered patio, there is an area where the plants are alive but not thriving. Reading from there will help as well. Wrong reasoning?

Correct reasoning but wrong season here for that with tropicals. Mine have been indoors for at least 6 weeks already and would certainly be dead if they were not.

Grimmy

 

[MiteyF]

I was under the impression Lux is hard to calculate as it is based on the reflection of the surface being exposed to the light... That being said I don't see any reason why what others use should not work. It would suggest however that a reflective setting such as Silver Mylar interior sides and back would help a lot...

Grimmy

Probably not a big deal with T8's, but for anyone using "big" lights, mylar is typically a bad idea, especially when close to plants. It will both trap heat, and can cause hot spots from reflection. Generally, flat white is preferred.

 

[Poink88]

Correct reasoning but wrong season here for that with tropicals. Mine have been indoors for at least 6 weeks already and would certainly be dead if they were not.

Grimmy

Understood! I missed that part and forgot how different your area is by now. Lowest we got so far is mid-40s and still getting lots of 70s.

BTW, check your PM.

 

[jimlau]

does this so-called Softbox Photo Studio Photography Reflector look like it would work? the inside is silver, I think composed of soft but taught material.

 

[GrimLore]

does this so-called Softbox Photo Studio Photography Reflector look like it would work? the inside is silver, I think composed of soft but taught material.

View attachment 44129

That could very well be the solution for you. I suspect that will also be able to handle a fair amount of heat. Also looks like they make a lot of sizes for not a lot of money.

Grimmy