DIY Grow Shelf

This is cross posted from Ourfigs.com.

As you can see from the picture I have gone overboard on fig cuttings this year. Many will be available for sale in April, but until then I needed to make room for all these cuttings as they grow. Since I am out of space in the unfinished side of our basement my solution was to go vertical. I plan to modify this design based on my experience with this first shelf and create more vertical space next season. In the meantime, here is how I built this first one and what has worked and not worked.

This is the final product. To get there I first had to pick an approach for lighting. I decided use LED strip lights attached to the underside of the upper shelf for light. These take up a minimal amount of room and are not too expensive. Initially I thought that two of these SMD 2835 strips would be enough for each shelf, but I ended up using 8 sets (4 sets of 2) on a single shelf, the top shelf.

https://www.amazon.com/gp/product/B0…?ie=UTF8&psc=1

The lower two shelves use this slightly more economical SMD 5050 double light strips.

https://www.ebay.com/itm/Double-Row-…72.m2749.l2649

I used two sets per shelf for the lower two shelves.

The lower shelves could be brighter, and I am waiting for a light meter to compare the light levels to my other lights that I know work well. I can add more sets later if I need to.

The lights come in 5M rolls. In order to make the runs the length of the shelves I cut and soldered the strips. The strips are designed to be cut and soldered.

Here are some of the lights in action:

To power the LEDs I used one 150W power supply I had from another project and bought one 600W one. The top shelf is attached to the 150W supply and the 600W powers the bottom two. One important thing to remember when wiring the LEDs is that you can’t put more than about 5M of lights in series without them getting dim due to voltage drop. So each 5M section has its own wire that runs back to a common place, where it is attached in together (parallel circuit) and then attached to the power supply. I originally thought I would use fewer LEDs, so the next one I do I will size for one power supply to keep things neater. I’ll also attach the power supply higher to make sure no water ends up in it. (Note that I still need to clean up some cords).

The 600W supply is this one:

https://www.ebay.com/itm/DC-12V-3A-t…72.m2749.l2649

One problem with the LED strip lights is that they don’t stick for any length of time to the bottom of the shelves, even though they have adhesive backs. The ONLY thing that I found that works is Gorilla Duct Tape from Lowes (other duct tapes don’t work). You can see I put small strips over the LEDs in three places per strand.

As shown in the pictures I surrounded the unit with reflective Mylar. Since my basement is full of figs I built this in place and didn’t have access to the back once it was built, so I taped the Mylar to the inside. It could also have been put on the outside. The Mylar helps reflect light back and also keeps light out of my basement. I don’t need it too tight, but I plan to build more of these next year and hopefully keep my basement windows from glowing purple in the evening and morning. I am pretty sure my neighbors wonder what the heck I am doing 

The Mylar I used was:

https://www.ebay.com/itm/SUPER-THICK…72.m2749.l2649

The thick Mylar is nice, but a thinner type would have been OK, especially for the sides and back. The reflective surface of the Mylar makes the shelves much brighter and I would highly recommend it.

One important feature of this shelf for me was making the shelves water proof. The 2X6s hold the pots in place, but are also caulked around the bottom to hold standing water. This keeps the water from running everywhere when I water, and also lets some water absorb into the bottom of the pots. Having a few hundred cuttings I water with a wand on a hose (once the cuttings have hardened off and can be soaked), otherwise it takes forever. On the tables watering results in a mess.

Finally, to make sure the plants don’t get too hot I installed one 120mm fan per shelf attached to a simple controller which has a temperature sensor that I tape under the fan. The fan is set to turn on at 28 degrees C. In practice only the top shelf sometimes turns on. The bottom and middle shelves stay around 24 C and 26 C respectively. It seems like good insurance though.

The fans are:
https://www.amazon.com/gp/product/B0…?ie=UTF8&psc=1

The controllers are:
https://www.ebay.com/itm/W1209-12V-5…72.m2749.l2649

Unfortunately it seems like the controllers reset when they loose power, so I hooked them up to an old laptop power supply that stays on all day. The power supplies for the lights are attached to a digital time. I use this type for all my lights and love them.

Here is the unit closed up. I tape Mylar above each shelf and use velcro on the bottom to hold it down. I also added an extra piece of velcro to keep the rolls up when I want them open.

Overall I am very happy with the unit. Watering is easier and the figs are really enjoying the warmer temperatures and seem to like the light levels. The leaves have turned a deep healthy green color over the last week, unlike the ones under my brighter LED lights that seem to be paler and suffer from the intense light. The project wasn’t cheap, but it was cheaper than tables and my T5/LED fixtures I use for them.