Cool vivarium 2.0

It would seem I have made the same journey that many people make when they build vivariums… starting off with something looking very close to nature, and eventually ending up with something a little more practical. Originally I aimed to recreate a little slice of the cloud forest in my inner city apartment and the result turned out great! Vivarium was fully operational in the beginning of May 2010. Everything was thriving and I was finally growing and blooming all these amazing cool to cold growing species that I had admired for so long. Life was good!

Cool vivarium 1.0

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Problem with EpiWeb

I had chosen EpiWeb for my build, a synthetic medium touted as a good alternative to xaxim. I liked the fact that it was an inert material that would not break down over time and by doing so changing its cultural properties. I also liked that it was light weight and would not get waterlogged. EpiWeb only hold 70% of it own weight in water and does not wick water by capillary action. At first I was really happy with the performance, but soon I would discover one of the main disadvantages with EpiWeb…

The roots would not seek to fill or remain inside the mounting blocks, they would just grow straight through. I want all my mounts to be movable so I can take plants out to photograph them, or perhaps move them if they need a change in culture (a drier rest period for example). But the mounting blocks would constantly get stuck on the back wall since it consisted of the same material as the blocks. The roots would grow hopelessly stuck in the material, the only way to move the mounts would be to rip off the roots. Perhaps I should have foreseen this, but still… I tried a few different solutions in an attempt to tame the roots. Like hot gluing weed barrier cloth to the back of the mounts, later followed by polyethylene dam liner. The weed barrier made the mounts more waterlogged causing mold to grow, while only stopping about 50% of the roots from poking through. The polyethylene liner did the job of stopping the roots, but it also made the environment on the back of the mounts very stuffy. No air would circulate though and there was considerable algae growth and mold forming. So obviously none of these “fixes” would do.

Another serious negative trait of this medium is that it is very hard to cut. You need sharp industrial scissors or a metal saw to do it. So because the medium is not porous like most natural materials like xaxim or cork, you cannot just break apart a mount to divide a plant. There is no way you can gently divide a plant mounted on EpiWeb as the roots would get so entangled in the material and any attempt to divide a plant would lead to massive root damage. The fibres would easily slice through the roots long before breaking. I grow many unusual species and I would very much like to be able to share them with friends in trade, not an easy prospect using this material.

Stelis gelidaEpiWeb blocks for the mounting of orchidsRoot project -hot glue gunRoot project Stelis sp.

Problem with fungus

The final nail in the coffin for me regarding EpiWeb and the natural looking vivarium design however was an outbreak of fungus that struck me late last year. It nearly broke my heart as I lost many plants due to this. I had accidentally turned off the fans in the vivarium (must have come near the button on the timer while cleaning). I was working many late nights at the time I did not realize the mistake for several days. Actually I first noticed the symptoms… leaves turning yellow and spotted, waterlogged sunken spots that rapidly spread through the collection. At first I quarantined the plants affected, but since I water by fine mist from above, the pathogens quickly spread throughout the vivarium, so quarantine was a futile effort.

It can be hard to tell the difference between bacterial and fungal infections, but most bacteria tend to thrive in warmer conditions than what I keep in this vivarium, so most likely I was dealing with some kind of fungi, or perhaps both. I begun treating everything with Physan 20, a broad range disinfectant, fungicide, virucide, and algaecide which is supposed to effectively control a wide variety of pathogens. I cleaned everything in sight then dipped all the plants and sprayed down the EpiWeb walls thoroughly with the Physan 20 solution repeatedly. Most effectively it killed all of the moss in the vivarium along with a few sensitive orchids, but I could not seem to get the fungus infection under control. Part of the problem I believe was that since the walls inside were covered in large sheets of EpiWeb I could not effectively disinfect the growing area. I think this is why the problem kept coming back.

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After a couple of months of battling this I finally got the advice from a friend to try Clearys 3336 F, a systemic fungicide. I decided to do one better. Before using the Clearys I wanted to rebuild the whole vivarium, converting the natural cloud forest into a bit more practical growing space that would be easier to keep disinfected and clean. This meant eliminating as much of the EpiWeb as I could. First I removed all the orchids, next I took down the internal EpiWeb walls och scrubbed the whole vivarium down with soap then sprayed it down thoroughly with Physan 20, making sure I covered everything top to bottom and keeping it wet for 15 minutes so the fungicide could do its thing according to the directions on the bottle.

Next I spent hours upon hours carefully removing all the mounted orchids from the EpiWeb mounts. This was a heartbreaking task as I had to sacrifice a lot of roots in the process, but I was determined to get rid of this awful material once and for all. Well, at least the blocks. I still have EpiWeb substrate in my pots, I have not decided what to do with that yet. It is not as critical to get rid of since the smaller nuggets are easier to divide, but soon I will replace that material as well. Just yesterday I had to release a Dracula bud from the substrate as it was not managing to push through. Once all the mounts were clear I could also assess the damage of the outbreak. It was clear that I had lost about 30 plants in total, and many others reduced as much as 50% in size. Very depressing. But it was nothing to do but to press on. I dipped all the orchids, pot, plant and all for 15 minutes in the Clearys solution, followed by all the bare root plants. This was an all day operation.

New design

Next I turned my attention to the reconstruction of the vivarium. I built an aluminium rack for hanging pots from, five rows with 14 pots per row, staggered so the water from the row above would not drain into the row below. I wanted to have plenty of air around the plants too so there would be less risk of more problems with fungus. For the mounts I made plastic mesh panels for the back and side walls. I attached it to some aluminium rods for weight and stability, then mounted them to the walls using the same holes I had previously hung the EpiWeb with. Simple and clean solution.

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As one more insurance policy for this I also designed a “rain proof” box fan for the bottom of the vivarium. A rectangular PCV pipe with four holes cut in it and two computer fans mounted inside. Then a louvered plate to cover each hole, louvers pointing up in the front pushing the air up, louvers pointing down in the back so the fans won’t suck in so much moisture. I left the ends open to allow for more airflow and also so water won’t collect inside, drilling a weep hole under each fan too just in case. The idea is to keep the air on the bottom and behind the rows of pots from getting stagnant. Works quite well actually. The added air circulation, new design and the fact that I will now be able to spray the hard surfaces in the vivarium down with Physan 20 at regular intervals as maintenance should keep troubles at bay.

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Finally, it was time to mount the some 200+ mini orchids again. I tested the water retention capacity of two different types of xaxim, hard (Dicksonia – left in the photo) and soft (Cyathea – right in the photo). But I think both kinds hold a little too much water for my liking. While dry the hard kind weighed 44 g and the soft kind 26 g. After soaking the blocks for an hour in water the hard kind weighed 70 g and the soft kind 110 g, so that pretty much said it all. The soft took three times longer to dry out as well… so if I was going to use xaxim, it would definitely be the hard kind, but it is a little difficult to get a hold of so I settled on cork instead. They say you should actually support the cork industry now that much of the wine industry has switched to synthetic. I found some all natural, heat pressed sheets online and made my mounting blocks out of that then using fishing line to tie the orchids to the cork.

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Many, many hours later, the minis were mounted and all the orchids back in the vivarium again. A few weeks have passed and I have sprayed all the plants thoroughly with Clearys twice more with one week in between. Everything looks good now and I think catastrophe is finally is averted. Thank goodness. All in all the plants were actually in better condition than I had originally thought, and after the radical treatment the survivors are looking very good across the board. I lost a few more plants to the treatment though, but not as many as I had feared. Although I am mourning a beautiful little Masdevallia that was lost…  Some flowers were lost too, but most buds faired well and several plants are now blooming again which raises the spirit too.

Cool vivarium 2.0

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This experience has been heartbreaking and very depressing, but I am not defeated, just a painful experience richer. The vivarium looks dramatically different now, but it works beautifully, more like a greenhouse. I kind of like it… at least I do not miss the old design with all the EpiWeb headaches. I am very pleased with this new setup and the orchids are already making a strong recovery.

By | 2017-10-13T11:25:41+02:00 April 22nd, 2012|Categories: Cool vivarium build, Projects|Tags: , , , , , , , |43 Comments

About the Author:

Karma is a digital nomad graphic artist and writer, orchid nerd and long-distance hiker from Gothenburg, Sweden. Former editor-in-chief for the Swedish Orchid Society magazine, published internationally and held lectures on orchid culture.


  1. Justin Tungate April 23, 2012 at 00:21 - Reply

    This is probably the best orchid blog post I’ve read. Sorry for your losses.

  2. Karma April 23, 2012 at 08:45 - Reply

    Thanks Justin!

  3. salaite April 23, 2012 at 18:21 - Reply

    I can only feel sorry for you, I have bought some Epiweb myself just when I started following your blog, but never managed to find use for it in my climate, now I’m glad 🙂 Hope your plants will recover soon!

  4. rj April 23, 2012 at 19:22 - Reply

    This looks much better! peatmoss and fine bark does it for me and not to forget the fact all the plants are about a week away from standing outside in the garden for the next seven/eight months!

    stil admiring you collection!

    best regards, RJ

  5. Karma April 23, 2012 at 21:10 - Reply

    Thank you salaite, I am glad you did not have to share any bad EpiWeb stories with me. 🙂
    Thanks a lot RJ, yes it is better isn’t it! So nice that you can grow outdoors for such a long season. 🙂

  6. rj April 23, 2012 at 21:29 - Reply

    🙂 and I live not that far away from you…
    only on hotter days it ain’t fun but giving much water keeps them cool even with 30+ temps i’ve had last year. even the masdies that aren’t that heat tolerant survived so it works fine with me. gets a bit crowded thought.. just can’t stop collecting 🙂 but everything for my seedbank!

  7. Karma April 23, 2012 at 21:39 - Reply

    Ha ha I hear you… hard to stop collecting. 😉 Wow, 30+ temps… we don’t really get those here, even on a good year…

  8. rj April 23, 2012 at 21:55 - Reply

    thank god not that much days… I want 10 degrees at night with fog and 20 degrees in the afternoon, but even in de andes there hot days. I know someone that saw Mas. nidifica growing in full sun while it was 28 degrees, don’t have to try that here as it would not survive. hot peaks aren’t that unusual but always for a short time, same for cold, I had them outside with the lowest temp of 2 degrees(forgot to get them back in…) and lost no plants , much to my suprise and much more to my joy! It’s stunning how tough they can be.

    well thanks for listening, see ya RJ

  9. Efi April 24, 2012 at 08:19 - Reply

    Keep walking Karma, we’ re following… : )

  10. Karma April 24, 2012 at 09:19 - Reply

    RJ, it is amazing how resilient orchids can be sometimes… I hope you have a good season outdoors.
    Thanks for the support Efi!!

  11. Mathias April 24, 2012 at 12:16 - Reply

    Awesome work on your vivarium!! I am just sorry I was not able to listen to the presentation you held for Östsvenska.

    • Karma April 24, 2012 at 12:35 - Reply

      Thanks Mathias! 🙂 Sorry I missed you in Stockholm too. Perhaps there will be other opportunities.

  12. Malin April 24, 2012 at 14:20 - Reply

    Looks really great with the new setup! Considering it too, I had some problems with algae some time ago, so my moss is gone and I’m not looking for that piece of nature in my apartment anymore! Like you, I want it more practical! Keep up the good work 😉

    • Karma April 24, 2012 at 14:23 - Reply

      Tack Malin! Practical is the word of the day. 😉

  13. Tony May 2, 2012 at 07:55 - Reply

    The original “Cool Vivarium” was a unique and inspired work of art. Looking back, like many vivariums and terrariums in my experience, what’s aesthetic and what’s practical, rarely come into a lasting balance–something has to give. As a fan of your blog, I’m happy you’re persevering. This new setup is all about the orchids and looks amazing for it.

  14. Karma May 2, 2012 at 08:10 - Reply

    Thanks a lot Tony! I think your assessment is right on the money, and in the end, it is the orchids that I am passionate about. 🙂

  15. Tristan May 10, 2012 at 08:58 - Reply

    Karma, thank you so much for sharing not only the ‘ups’ of your orchid projects, but these downs as well. It’s so inspiring to see a grower so dedicated to providing the perfect habitats for her plants, I’m glad you’ve bounced back from this difficult time, the new viv set-up looks terrific.

    • Karma May 10, 2012 at 09:01 - Reply

      Thank you very much for the kind words and the encouragement Tristan! 🙂

  16. air June 5, 2012 at 06:33 - Reply

    Hello Karma, love your work! I’m from Australia and am in the process of setting up an epiphyte wall / open aquarium for orchids and other plants. And fish of course! Thanks for sharing your experiences, I’ve got some great ideas from your blogs. I will have to document my build and will be sure to share it with you when done. Currently I am sorting out a misting system and making a ducted fogger. Here’s an early photo to tease you! Best regards, air.

  17. Karma June 5, 2012 at 08:19 - Reply

    Thank you! 🙂 Looks like a good start of a very interesting build. I look forward to seeing how it turna out!

  18. Erik June 26, 2012 at 03:41 - Reply

    Very cool your terrarium, like the irrigation system. I’m from Brazil, Pará State, practically in the state capital, the orchids grow in the streets in hoses centenarian, but the varieties of high-altitude climates do not go here but I have some Nepenthes are Lowlanders …

  19. Karma June 26, 2012 at 09:04 - Reply

    Thank you Erik! We do not see many orchids outdoors growing wild here, only in a few special places. Must be nice to see them almost everywhere. 🙂

  20. Erik July 23, 2012 at 04:49 - Reply

    Not everywhere, but what an exception in my region and most common micro orchids and bromeliads, but what I really like are the nepenthes but can only have Lowlanders, but returning the orchids can not grow Draculas they do not hold out the heat here. Eentão so I can have orchids and nepenthes in the case of climate varzea Lowlanders.
    There I have to mention that a friend has a golden shower orchid that has gripped the OrquidaRio it, and this orchid in my area and I think it was more than 50 buds of a single plant.

    up to more hugs

  21. Manuel Lucas July 28, 2012 at 11:29 - Reply

    Congratulations, Karma. It looks superb (and you do keep an extremely efficient brain inside of your head) :-))

    • Karma July 30, 2012 at 22:34 - Reply

      Thank you very much Manuel! I do my best. 🙂

  22. Elizabet Biren November 13, 2012 at 01:54 - Reply

    Hi. I believe there’s some thing wrong with your links. I hope you can fix it!

    • Karma November 13, 2012 at 09:58 - Reply

      Thank you very much for letting me know. I think it is fixed now, does it work for you?

  23. Jake November 4, 2013 at 01:19 - Reply

    Ever try EM 1? A respected orchid enthusiast recommended this product to me at an orchid show recently. its a live microbial product so it should be safe for your orchids!! Very nice set up btw!

    • Karma November 5, 2013 at 09:36 - Reply

      Hello Jake. Thanks for the tip, I will look into it. I have never used it but it sounds interesting. 🙂

  24. Giorgio March 8, 2014 at 18:50 - Reply

    Great work, truly inspiring!! ^__^
    What are the sizes of pots?
    Where have you bought them?

    • Karma March 8, 2014 at 18:53 - Reply

      Thank you! 🙂 The pots are 11 cm and I bought them at the local garden center (Plantagen). They are intended for pond plants. I like them since they drain really well and are well ventilated.

  25. SteveR January 1, 2015 at 16:37 - Reply

    I’ve been using aquariums as miniature orchidariums with a few plants each, but I’m awestruck by your project! Maybe it’s time to expand…our local Botanical Garden is having its annual orchid show in about a month, and they always have lots of nice plants for sale, plus the Orchid Society is having their annual show and sale too. I absolutely can’t have more plants until I find more space, so I couldn’t have stumbled across your blog at a better time!

    • karma March 13, 2015 at 13:45 - Reply

      Nice to her my blog was an inspiration to you! Good luck with your projects!

  26. Elizabeth March 7, 2016 at 16:57 - Reply

    Sharing Justin’s sentiments, this is the best orchid blog I’ve come across. Thank you for so openly sharing your heartbreaking experience, the clever remediation and re-engineering of the room. You’ve got me thinking about my own environment differently.

    • Karma March 7, 2016 at 18:46 - Reply

      Thank you Elisabeth! 🙂 Very nice to hear that you like the blog and found it helpful when planning your own growing space! Take care!

  27. bulbopillum April 8, 2016 at 20:28 - Reply

    Hi ! how do you get the moss to grow on the epiweb ? i also have an epiweb vivarium but no moss is growing whatsoever …

    • Karma April 8, 2016 at 21:53 - Reply

      Since EpiWeb is not organic material you have to prime it and sow the moss or it will take ages to sprout any moss on its own by transferrance. Buy some moss seed, or collect moss suitable for the microclimate in your vivarium (collect from your own mounts?). Toss it in a blender with some sphagnum moss and water. Spread the paste on the EpiWeb and wait. Make sure it never, ever, dries upp before growing well and maintain good light and humidity. Good luck.

  28. Mike June 14, 2016 at 23:12 - Reply

    Wow! I visited your blog when the vivarium 1.0 was built and thought it was really great. Sad to read your story on losing so many plants and all the headaches from epi-web. BUT very great to see the 2.0 version being better than ever now. Thanks for keeping up such a great orchid blog!

    • Karma June 15, 2016 at 08:16 - Reply

      Thanks Mike! Very nice to hear! 🙂

  29. Ramesh July 9, 2016 at 21:13 - Reply

    Hello Karma. I came across your website / blog the other day. I must say if has been one of the best orchid websites I’ve read. I have learnt a lot about orchids and I found your article on the Vivarium build fascinating. It has certainly got me thinking. Keep up the excellent work and I for one will be closely following your site. Thank you.

    • Karma July 9, 2016 at 22:05 - Reply

      Thank you Ramesh! Very nice to hear!

  30. Jacob August 16, 2016 at 19:43 - Reply

    Hi Karma. While I was doing some orientational reading about how to make an orchid vivarium I run into your blog and this blog is really amazing with everything you share here, thanks! I am a beginner with orchids, a trip to Meghalaya (India) made me interested and now a few months later I am hooked 🙂

    I have a question about your vivarium height, do you find that 160 cm is a good height for a vivarium? Are the plants on the bottom still get good light?
    I was planning to make a vivarium 125cm wide 75cm deep and 100cm high, do you think that is a nice sice or should it be higher? I was planning to use 25.000-30.000 lumen LED lights. It would be my first one so I don’t have much clue yet..thank you.

    Cheers from Holland

    • Karma September 21, 2016 at 14:06 - Reply

      Thank you Jacob! Nice to hear that you found this site helpful and inspirational. The taller the vivarium the more thought you have to put it to lighting it, just as you already are doing. Depending on what you want to grow it may or may not be an issue. I successfully grew and bloomed several different species on the floor of mine, but all of them with low light demands. I bought a used reptile cage as my vivarium, so the size was set, doing it to spec I might not have made it so tall, 100 cm tall would probably serve you well. Keeping in mind it is easier to establish a good micro climate in slightly larger spaces… the smaller the space the harder I think. Good luck!

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