Aquarium --> Orchidarium Conversion
 

At the beginning of 2023 I picked up an old aquarium from the salvage shed at the dump. I had been researching paludariums and planted tanks, so my original plan was to do a paludarium build, but I discovered a small crack near one of the corners and decided it probably shouldn't be used to hold water...

I came up with a new plan to build a heavily scaped orchidarium inspired by some of the paludarium builds I had been looking at. I wanted to orient the tank vertically, so I bought an aquarium conversion kit from I Heart Geckos - basically an acrylic panel and hinged door that I fixed to the top (now front) of the tank with silicone sealant. I used spray foam and driftwood to scape the back and one of the sides.

Some of the paludarium tutorials/blogs I had looked at covered the foam with coco coir (glued on with silicone) for a more natural look, and some used hygrolon to mount plants to. I decided to trial both methods so I covered the foam on the back with a sheet of hygrolon and siliconed coco coir to the foam on the side wall. I wasn't planning on mounting any orchids directly to either surface, but was hoping the coir/hygrolon would be a good surface for moss and a few climbing terrarium plants to grow up. I also had a lot of fun creating interesting drapes and folds with the hygrolon which I thought would look amazing covered in moss.

I placed my first (and last) order with Ecuagenera for pickup at a local pop up event in February. All of the plants were in ROUGH shape - I lost 2 within a week, and the rest needed serious rehab which delayed the orchidarium planting by a couple of months. Four more plants slowly perished, and a couple of others didn't show a lot of improvement but also weren't actively getting worse. I think there were only two that like actually seemed like they were going to recover. I was super impatient / having a hard time dealing with the delay in my super exciting fun project so I decided to go ahead and plant the orchidarium, hoping that the struggling orchids would like those conditions better. I planted it in the beginning of May with the following species:

Orchids
Leptotes pohlitinocoi
Bulbophyllum medusae
Bulbophyllum maquilingense
Bulbophyllum retusiusculum
Trichosalpinx orbicularis
Haraella odorata
Ceratostylis phillipinensis
Specklinia grobyi (mounted on cork slab)
Anathallis funerea (mounted on cork slab)

Non-Orchids
Pleopeltis polypodiodes (resurrection fern)
Lemmaphyllum microphyllum (miniature epiphytic fern)
No ID Microgramma sp. (miniature epiphytic fern) x2
Philodendron Burle Marx Fantasy
Solanum sp. Ecuador
Selaginella unicata
Marcgravia rectiflora
Pyrrosia piloselloides (mini epi. fern)
Pepperomia emarginella 'Ecuador'
Pilea peperomioides
Ficus punctata 'Panama'
Ficus sp. 'Borneo'
Raphidophora pachyphylla
Solanum sp. 'Ecuador'

The bottom of the tank has a thick layer of LECA, landscape fabric barrier, then a respectable layer of super chunky jungle-y media (LECA, coco husk chunks, bark, charcoal, splash of potting soil). There's not a lot happening down there at the moment, but I'm hoping to plant some terrestrial orchid species down there once I get other elements dialed in a little more.

I took some photos today while doing maintenance on the tank to show it off a bit - this is about 3.5 months of growth. I've definitely learned a lot, and there are definitely things I'd change if (when) I make another tank:

Watering/Misting
I have a reptile mister with automatic timer/schedule set up right now, but I've been struggling to figure out a good combination of frequency and duration. It either seems too wet for too long, or when I turn it to the next lowest setting, it seems like things are drying out and staying dry too long. The system I have only has predetermined frequency/duration settings, so I may eventually switch to something that I have more control over.

Drainage
I wish I had thought through this more and figured out a way to install a drain outlet/sump pump. Since the only 'drainage' is a layer of LECA, I have to be careful not to let the standing water in the bottom get too high. I'd like to be able to occasionally turn the misters on for a long time for a thorough soaking without all that water pooling.

Plant Placement
It would have been smart to test out the plant placement before committing. I'm a little worried the Leptotes is staying too wet since it's near the misters at the top of the tank. It's mounted to a bare piece of wood, and it seems to be rooting well, but the branch has a bit of a convex shape that collects water near the base of the plant. I've been keeping an eye on it in case I need to remove it, but I'm hoping it will be ok. On the other hand, the Trichosalpinx is so low in the tank that I worry it doesn't get enough water (misters are only at the top). I mounted it with a bit of sphagnum, but the moss gets dry and I have to supplement misting/watering this plant daily. It's started putting on a lot of root growth recently, so hopefully it's happy.
The Bulb. retusiusculum from Ecuagenera is ~finally~ starting to put out some new growth and a few new roots, so I think that one is going to be ok, but the Bulb. medusae never grew roots and is slowly declining. I'd be surprised if that one survived (probably would have been too big for the setup with flowers), so I may be able to do a bit of rearranging once that one gives up.

Hygrolon/Coco Coir
I had a vision of a mossy blanket covering the back and side of the tank, with moss growing down some of the branches, but I don't think it's going to happen with the current setup. I applied some 'dusk moss' mix to try to speed things up, but the coco coir layer is so think it doesn't hold any moisture whatsoever (silicone glue doesn't help either), and the hygrolon doesn't wick nearly as much as I was anticipating. To keep those surfaces moist enough for decent moss growth, the misters would have to be on longer than the orchids could handle. There's been a little bit of moss action, and some of the moss that came with a few of the orchids has been doing well, but I think a lot of the tank is too dry for it to spread well and survive.

I'll update this thread with more photos in the future!

Photos of the full tank:
https://imgur.com/BFEhOmH.jpg
https://imgur.com/sVxGDL1.jpg

Leptotes pohlitinocoi (and friends):
https://imgur.com/P3685Km.jpg
https://imgur.com/4jABZhQ.jpg

Bulbophyllum retusiusculum surviving/starting to put out new growth/roots:
https://imgur.com/WIVQM7I.jpg
https://imgur.com/XU2UIc7.jpg

Bulbophyllum medusae (left) suffering, Bulb. retusiusculum (right) surviving (and friends):
https://imgur.com/u1tR8O6.jpg

Trichosalpinx orbicularis not loving life, but not really hating life either:
https://imgur.com/fmh1qly.jpg
https://imgur.com/mgqxDOJ.jpg

Haraella odorata with a cutie bloom:
https://imgur.com/sqzFQhC.jpg
https://imgur.com/sFBRjzy.jpg

Bulb. maquilingense (my absolute favorite) (front) and Ceratostylis phillipinensis (back). Ceratostylis has developed some weird dark spots - they don't appear to be progressing, but it makes me a little concerned...
https://imgur.com/57CZBZ6.jpg
https://imgur.com/rFFjSDQ.jpg
https://imgur.com/mL4EPem.jpg

Top of the tank - I think this section of the tank looks really nice:
https://i.imgur.com/ikQnSk5.jpg

Love to see a picture if you have any.

I'm having a hell of a time uploading photos... Working on it now, so hopefully they show up soon!

This is fantastic and great timing! I just tore down one of my tanks and am going to convert it to an orchidarium.

Thanks! I’d love to see pics of your conversion, sunfire!

It looks fantastic! My only concern is how wet it looks and what seems to be a lack of airflow. Always good to have a fan if you can get one in there or at least attached to the outside of the ventilation holes.

As for your misting schedule, I would definitely try to find something that gives you a lot of control, or else you need to rely on something like fans to compensate for too much wetness, etc.

Keep it up!

Thanks, kcpi3141. I had just done a light feeding right before snapping the pictures, so it's definitely not typically that damp in there. I also have two small computer fans that hang from suction cups on the ceiling and run 24/7, but they're pretty clunky and visually block some of the higher up orchids, so I took the pics before re-hanging them for aesthetic reasons.

I’m about to have an empty 40 gallon and 10 gallon aquariums. This is really well done. Thanks for the inspiration.