A laminar flow hood is not just for the labs, you can do it too!
In the past I have relied on three different labs around Australia for my Cymbidium orchid flasking needs. I use each lab for a different reason and a different service. They are Western Orchids, Barrita Orchids, and Flora Laboratories.
The service is excellent from all three labs, but the ability to sow green pods and replate my own flasks was something I really wanted to try and master. It means I can control the timing and the cost of the service.
After years of sending Cymbidium green pods to a lab for sowing I began looking at the options of purchasing a laminar flow cabinet. At the time though, it was a costly exercise to purchase something new. And the second hand market was pretty much non existent. It’s a pretty niche market…
The only option was the DIY option!
So, if I couldn’t have the real deal, the only thing to do was make a laminar flow hood myself. So after several hours searching the internet, I had decided on a model to use and started ordering my parts.
I now have my own Laminar Flow Hood to enable me to sow Cymbidium orchid pods at home. How cool is that?!
And for the record, I will still use these three labs going forward for specific services. But for basic seed sowing and replating, I’ll be doing that myself from now on.
Why Laminar Flow for Orchid Flasking?
Flasking orchids demands a sterile, particle‑free airstream so your open media, tools, and seed stay protected from airborne contamination. With horizontal flow, filtered air continually sweeps across your workspace, which makes the process easier and far more consistent than wrestling inside a still‑air or glove box during repetitive replates.
If you only sow occasionally and need to keep costs down, a glove box or still‑air box can work. The trade‑off is reduced ergonomics and a higher risk of hand‑induced turbulence compared with true laminar flow. You’ll find an example of a still‑air box at the end of this article.
The Design
Firstly, I purchased a stainless steel table top from a local Facebook Marketplace seller for quite cheap. I really wanted to work on a surface that was easy to keep clean. Stainless Steel has to be the best option in my opinion, hence the extra expense I went to to obtain it.
For the design, I found a YouTube video on All the Gear, No Idea. This is pretty much a follow the bouncing ball tutorial on the concept, design and building of a DIY laminar flow hood. Hoocho is a very relatable Aussie who just finds a way to get it done! He makes some mistakes in the process of his build, so that we don’t have to!
There isn’t much to it, however, the basics include using a high grade HEPA filter, like H13 or H14, and enough airflow to make 0.5m/s of flow through the hood. This is fast enough to blow contaminants out, but not create any turbulence.
A list of parts Hoocho uses in the build is included in the description of the video, so everything you need is there. Have a watch of the video now. Then come back to this article for details on how I modified my build to suit me.
The Build
My design was based on Hoocho’s, however, I wanted some more space to work in. So my design ended up being wider that Hoocho’s with a bigger flat panel filter. The dimensions of my unit were about 620mm high, 760mm wide and 600mm deep. My flat filter was 30″ x 20″, so 4″ wider to give me some more room to work in. To decrease the weight of the box, I used 12mm plywood . I obtained my ply as offcuts from another Facebook Marketplace seller, so it was super cheap!
I purchased the same inline fan, which is quite an impressive unit. But I also added an extra Hepa filter (three in total) to increase the intake surface area for greater airflow. I’m sure there is another solution to purchasing a larger Hepa filter instead of three small ones. However I was able to source these 40% cheaper than retail, so it worked for me.
A steady smooth stream of air is the key.
I chose the horizontal flow model, which pushes HEPA‑filtered air from the back wall across the bench to the front opening. This keeps the filter well away from hand/arm shadows and is popular for benchtop tissue culture work.
You could also use a vertical flow model, which comes top‑down through the work opening. This can be taller and sometimes more forgiving to place in small rooms, but tool placement and arm movement matter to avoid creating eddies.
Either route can succeed if you hit ~0.5 m/s at the work plane and avoid obstructions that cause turbulence.
I have also mounted a light on the inside to ensure it’s nice and bright to work in. I painted my hood white using left over gloss anti mould bathroom paint from the shed to aid in cleaning when I need to.
So for under $500 I had a stainless steel table top and laminar flow hood that I was able to build myself, and quickly. (The below items I used contain affiliate links. If you click through and make a purchase, we may receive a commission (at no additional cost to you). As an Amazon Associate, we earn from qualifying purchases.)
The major components purchased in this build for my laminar flow hood were purchased from Amazon and Bunnings.
H13 HEPA Filter – which is a medical grade filter. This was purchased from Bunnings Australia.
Ducturbo 8 Inch Inline Fan. This was purchased from Amazon.com.
K & N 20″ x 30″ Panel Filter. This was purchased from Amazon.com.
The Results
I ended up building a smaller version of the full‑size cabinet I originally wanted, but it works exactly the same. Since finishing it, I’ve sown several green pods and replated multiple flasks. I haven’t had any contamination so far, and I credit that success mostly to careful preparation.
The cleaning and disinfecting of the tools you use to work with is of utmost importance.
Disinfect your tools often and don’t use the same tools for different pods or flasks. Wear gloves and a mask, and spray everything down with 100% isopropyl alcohol often. We also heat our tools on a flame to burn off any potential contaminants.
Start your hood at least 10 minutes before using it to create that airflow and remove contaminants.
There are many You Tube videos out there that show you the techniques of preparing green pods for sowing and also the cleaning of your tools. And we will also post some of our own to assist you.
Here at Orchid Wise we use orchid sowing and replate tissue culture from Western Orchids. Western Orchids are local to us and we have had incredible results with this growing medium, seeing flasking times decrease to as little as 13-15 weeks from replating small plantlets. Germination is always a little unpredictable, but once they are growing, plants are kicking along at fantastically quick speeds. We couldn’t recommend Western Orchids tissue culture enough!
Other Options…..
Flat Pack Laminar Flow Hood
I have since found one of a number of websites in Australia that will provide a flatpack of pretty much the same hood that I made.
My hood though is deeper on the sides. Personally I think that may provide some better protection from contaminants working their way in.
Aussie Mushroom Supplies sells laminar flow hood flatpacks online, and you simply assemble the unit when it arrives. A flatpack gives you every part you need in one box, while I had to track down components from several suppliers and cut all the timber myself.
They are certainly more expensive than what I was able to make, maybe about double my cost, but if DIY is not your thing, then this might be worth a try. The sizes vary, as do the costs, but a medium to large size would be very useable.
For our overseas friends, it seems DIY mushroom growing suppliers offer the best value for laminar flow flat packs, so search on Google and no doubt you will come up with a load of options.
Still Air Box
A Still Air Box offers another great at‑home option you can build yourself. You can see one in the photo below. It costs far less than the setup I built, which makes it perfect for anyone on a budget, and it keeps contaminants out of your flasks just as effectively. Many experienced flaskers use Still Air Boxes at home with excellent results.
Again, there are plenty of You Tube videos on Still Air Boxes and how to make them and use them effectively, or they can be purchased from places like eBay and etsy. A Google search is your best friend here!
So there it is. Get out there and build your own for a value way of expanding your hobby!
Happy flasking!