Hi all, first of all sorry about my english. Have been thinking a lot about indoor lighting for cactus, specially the columnar ones.

After lot of years building led lamps for cannabis growing, and nowadays interested in cactus indoor cultivation, I started to think that the architecture of the columnar cacti makes difficult to light them efficiently using top lights.

When using low heigh cacti and lot of them, there is no problem..you can use new efficient led lights like quantum boards or led strips and more or less the cacti got nice light

The problem arrives when you have a few cacti and you want to light them using the less posible power..You can use a led spot light over the cactus, but the top of the cactus will got a lot of light..and the laterals much less..Plants with leaves have not this problem cause they can move the leaves towards light, but cacti has almost all their photosynthetic surface not facing directly the light.

Using top led lights,when I measure the PPFD at the top of the cactus I get 250 ppfd in one of my setups..thats not bad considering a 16/8 photoperiod schedule...The problem is that the sides of the cactus, receive much less light..only about 70 PPFD, and at the end the majority of the surface of the cactus is at the sides...I mean in columnar San Pedro types, not peyotes of course..

So I decided to make a little lamp for individual cactus that overcomes this issue..Using very little power so you can light much more efficiently the San Pedros..

For lighting I used led flexible strips of Samsung 3500k lm561c ..those strips can be cutted every 10 cms. and maximun recommended power is about 2 watts every 10 cm of leds.

I decided to make a simple frame for the lamp using only 3 different pieces that I designed and 3d printed. The 3 pieces are printed 3 times each one to make the lamp frame..so 9 total pieces..
Some pieces are designed to allow the lamp to expand its diameter in an easy and simple way.

This are the pics of the lamp I built

https://imgur.com/VTpQH6M

These are the three main pieces that have to be printed 3 times each one

https://imgur.com/IcbXFQv

The pieces joined

https://imgur.com/EODooRg

The main frame expanded to adapt to several other sizes

https://imgur.com/543Fecm

The lamp with led strips mounted

https://imgur.com/SMiQRJU

I positioned an old cutting that is developing roots just to see the effect...

I measured the light at the sides using an spectrometer...with 12 watts (maximun potency) it was about 450 ppfd...thats a lot! so I can dimm the lights until find something like 100 ppfd..doing that will also increase a lot the efficiency of leds ...and reduce also the a lot the potency needed. So at the end..you can have a much better illuminated cactus..with much less power..and is very cool to look at..it can be used as a normal lamp in a room..
Of course if you surround the lamp with reflective material it will be much more efficient...
I used 3 led strips cause the leds have about 120 degree light emission..so they cover the 360 degree circumference
Hope you like the idea

Awesome design-I've been meaning to do an LED build for some time now but this one is perfect for cacti cultivation. I'm still pretty new to setting up these sorts of custom lighting fixtures, so if you don't mind me asking, how do you hook the Samsung 3500k lm561c strips up? Do you micro-soder the wires or just crimp them? Also what kind of driver do you use?

I've watched a gromau5 series on this subject on Youtube because I'm very interested in setting something like this up for my grow, and I want some suggestions

Thanks for your comment, there are special connectors for this kind of strips, they are cheap and also exists several types..some are for connect the end of the strips when you cut them or for connect to another strip..etc...
You can find them online easily. Is not necesary to solder..just attach the flexible strips to the connectors as you will see in the pics I show..
I use a generic driver..these leds use 24 volts at maximun voltage..and the driver has its ow dimmer..is a cheap one..If you want better quality go for Maxwell drivers..
I used Constant Voltage led strips..so the driver is a cheap one for Constant Voltage (the most used ones) but you can use also Constant Current leds so the driver should be for Constant current..
This kind of lamp is done for individual cacti...if you have lot of them you should use a lamp from above better..
The frame is made of plastic..so if you are gonna use the leds at their maximun potency..is better to use a heat resistant plastic or made an aluminium frame..As I plan to run the leds very sofly I can run them without heat sink..
Probably rigid led strips with aluminium sink built in is a much better solution, but I have those strips unused ..and also they are very cheap..

https://imgur.com/VZqk1v0

https://imgur.com/CfqYltf

https://imgur.com/ASQlBS5

I appreciate the response. You make it sound pretty simple to get into. I'll keep constant voltage LED's in mind. I'd also probably opt for aluminum just for the peace of mind. I know Samsung makes great products in lighting department, and strips seem the most flexible in terms of application. I just picked up some 5 gallon buckets and may try outfitting one of them with something similar.

Anyway, good luck with the grow. It would be interesting to see a side by side growth comparison of your new design verses a standard overhead bulb grow.

Well, I used constant voltage leds cause I have them previously and also I have the driver for them, but keep in mind that Constant current is in fact a more efficient and safe way to run leds..
Being said that..leds can work both ways... Most grow led lamps work in Constant current for the reason I am talking about..however the cheap flexible strings usually are designed for Constant voltage...just because are easy to drive and use..
So when you gonna buy some led lamp...look for Constant current instead...
Also remember that for flexible strips to be efficient they must have good leds inside, like the samsungs ones I named...and usually what you can find in common stores are strings with not efficient leds ...

What do you think about using these: https://growlightsaustralia.com/product/buddies/ , white 4000k ones?

In a bigger area, like a tent with overhead leds, dangle these vertically throughout?

Seems like a pretty simple approach.