Topic: I built my own DIY light grow box.

[gavinjconway]

So….. I was sitting at the Christmas dinner table (on boxing day) with the family and suddenly decided I need a grow box to play with for growing some show onions, a few peppers and chilies.. Bright idea…

I had a light box of sorts sitting in my garage for layering my vinyl signs which I had made out of an old cupboard from a skip with some lights inside and a perspex top. Basically a box to lay signs on and then lay another one on top in the correct positions to create different backgrounds etc. I don’t use it any more so decided it can be DIY’d into my new grow box.   

I removed the lights and door, hacked it shorter and started on the new design. I had previously used 6 energy saver bulbs and had some plugs and switches in my draws.

I decided on using 2 bulbs and have them adjustable so I could follow the growth from small to quite tall as the box was now just under a meter tall!! So I got stuck in and made the light carrier bar to be adjustable and also decided it may need some air circulation so I dug out some old PC fans that I collect from dead computers. The box had holes top and bottom for convection airflow as well. There would be no need for separate heating as the bulbs would get hot and heat up the air inside. I also purchased a temperature controlled plug unit to control the cooling/circulation fan. The whole inside of the box is lined with aluminium foil to reflect light and the two bulbs have a reflector to reflect light downwards as well. It also has a “Peek a Boo” flap to look inside without letting precious heat out. To run the fan I found an old mains adaptor like you get on Christmas tree lights or phone chargers and the fan will run on about 6-12 volts so most old adaptors will be fine. I have a few spare that I collected over the years so any breakdowns can be sorted asap.

 I put everything together and it really looked good. Then I was Googling about grow-lamps and realized that the bulbs I had were not the right light spectrum for growing purposes so I had to buy others to suit. I went for CFL type helical design (compact fluorescent lamp). The bulbs are 30W - 6500k but are equivalent to 150W  incandescent light in old terms and only cost under £3 a month to run 24 hours a day.

I made a pile of seedling supports with kebab sticks and copper wire to use what they start to grow and need supporting. It all really turned out well but it was soon full with only a handful of seedlings put inside!!

Oh well – back to the drawing board….. and re-make it as a bigger but not as high unit. Really just turn it on it’s side.. and make a new light carrier, move some of the electrics, move the perspex door…. etc.

I stripped it out and started again. Now that it will be longer I need another bulb – luckily I bought 5 and I had a few spare light fittings. The light carrier is now also stronger and simply gets screwed in place to the height as required.  Put the new design together and all looks great. I still need to foil the light carrier bar and find a big reflector as the original one I made is now too small with the added extra bulb.  (It is also longer and I can place my chitting potatoes on top as it is placed where I normally do the chitting).

The temp controller clicks in the fan at 21 degrees C and runs for a few minutes every now and again. This brings in cold air and blows it in from the top and will circulate the air at the same time. I have covered (with aluminium foil) most of the previous holes with I had cut out for convection airflow and  left two each side. I can easily just punch the foil to open more if the temp remains too high and have more PC fans to add if required. My plan is to start some show onions, chilies and peppers off in the propagators then move them into the light box after they have started to grow. About 6 weeks with 24 hours a day light then down to 12-16 a day. I dont know how long they will stay in this box due to the height. I have a problem of when the seedlings out-grow the box height!!! Maybe have to sneak them into the conservatory without my wife noticing…. bit difficult!!

Notice the new smoke alarm I fitted above it – just in case!!

 

[gavinjconway]

Potted on a few more tiny onions into small pots and put into the light grow box. it seems to be working as the chillies, peppers, onions and leeks are really doing well.

One new leaf every 7-10 ten days are growing from the onions. leeks a bit slow but seem to be growing well now.

Chillies/peppers are still in their original modules and not potted on yet.

 

[digmore]

Gavin,

Very smart, how long did it take to build.

How far does it advanced the growing cycle ?

Digmore. 

[gavinjconway]

I had the basic box done for my grafix side so to cut and modify really took a few hours. I did it standing up first then modified to be on it's side to have more room.

About advance in growth... I put my just germinated pepper / chilli seedlings in it on 27 Jan and some are now 2-4" high.

My onions - some were sowed in the small pots, and germinated in the box but generally they have all been pre-germinated in the propagator and potted on and placed in the box. My bigger onions are now about 8" tall and 3-4mm thickness with 4-5 leaves each compared to small thin spindly little seedling brothers which are still in the trays with maybe one new spindly thin leaf.. So I'd say the light has made a huge difference. About 4-5 leaves of difference.. I'm told the onions need 24/7 light and for about 6 weeks so they grow a new leaf a week and then down to 18 hrs a day light. I have all sorts of ages so going to be difficult to do that. I may have to make another box to separate them a bit and cope with ALL the seedlings I'm doing!!

p.s. these onions are only for show. 

[Jayb]

Looks fab, good job 
Chillies and peppers look great.

[gavinjconway]

Thanks all.. I'm having fun with it and thought I'd share it with you.

[gavinjconway]

Digmore, if you look at this pic the small spindly onions on the far left are what I pricked out today been sitting in the cold'ish conservatory. They were sown about mid Jan. The rows in the foreground are the biggest I have so far and were sowed early Jan so 2 weeks earlier direct in the small pots. The other medium sized are all the same batch as todays ones - I just never got around to pricking them all out at the same time. So you can see the difference is like chalk and cheese..

[digmore]

Morning Gavin,

Good clear pics, shows the difference in growth. Would you say the advancement is about 4/6 weeks over the plants growing cycle. If you kept the plants in the box, conditions constant would they bolt/spindley or mature correctly.

Digmore. 

[gavinjconway]

Yeah I'd say they are at least 5-6 weeks ahead now. I don't know if they will bolt sooner or go spindly or not. I'm just going by the instructions from exhibition-seeds.co.uk where I got the Ailsae onion seed from. It's the first time using any lights so a learning curve for me.

[digmore]

Thanks Gavin,

I am interested to see how you progress over the year, please keep us posted, good or bad, lessons to be learned.

Digmore. 

Ps. Could this be used over the winter period ?

[gavinjconway]

Ps. Could this be used over the winter period ?

Mmmm - I'd say that if you started chillies/peppers/aubergine and onions they would probably grow really big.... maybe I'll look into it.