Bonsai in Aquariums

Redwood Ryan

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Hey all,

I've been reading about people using aqauriums as greenhouses for their tropical bonsai and I thought it sounded like a cool idea. People put gravel and charcoal at the bottom of the tank and put a small amount of water for the humidity effect. Does anyone have any personal experience with this method or see any issues with it?
I think you would have to be careful not to create a swamp / marsh. You would have to lift out all your trees and water them separately, which might be a hassle. Additionally, you would have to have a clear cover to keep in the humidity, while letting in light. You might also want a small fan in the aquarium to create air movement so your trees don't get fungus.

I think a slight twist on this would be to use an acrylic aquarium (they are cheaper than glass, anyway), and drill one or more drains into the bottom so that you could hose down your trees in the tank, and any excess water would drain out. Plus it would allow you to have a bare bottom tank which would help a ton with maintenance. You would just need something to keep your pots from sitting in water, which might be as easy as cutting some pieces of eggcrate lighting screen material and setting them in the bottom.
Thanks BNut!

Acrylic is a great idea! But the reason I wanted the water sitting at the bottom was so that there would be humidity in the tank and I figured that would be an easy way to create it. Have any other ideas on how I would create humidity in the tank? Thanks again!
A reptile heat mat under the tank perhaps?

I use one during the winter to keep my bay window frost free.

If i want humidity i leave a film of water in the gravel trays the pots stand in.
I made a wooden frame to separate the window ledge from the plastic trays so condensation could not accumulate under them.

These frames are topped with a carpet tile and the reptile mat lays between these tiles and the trays.

I opted to control the heat with a rotary timer as i could not find a thermostat at the time.

As an added advantage your tree frogs would find themselves at home.
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It wouldn't take a lot of water to create a lot of humidity. If you hose down your plants, and then put a lid on, the aquarium would be plenty humid - maybe TOO humid. If you needed a little more humidity you could always add a humidity tray or put some moss on the bottom which would soak up any extra water while staying damp.

Regardless, you wouldn't want to "guess" about your humidity - you would at the minimum want a humidity meter and thermometer. You can get something electronic and fancy like this for about $50 at Amazon. You can also get smaller manual ones for lizard enclosures for about $15-$20.


While you're at it, you can always get a fogger if you REALLY want cool humidity :) Then people will be really impressed with your spooky bonsai enclosure :)
I picked up a weatherstation with a little outside transmitter,this sends temperature and humidity data to the weatherstation from the bay window.

Thus i can watch tv,browse the internet,and keep abreast of developments by simply moving my eyes.
I suspect it works about as well as growing fish in a bonsai pot...
I suspect it works about as well as growing fish in a bonsai pot...

Well... at least there is some history here with terrariums...


A lot depends on where you live and what is available to you. I knew a guy who would overwinter a HUGE ficus bonsai in his kitchen in Chicago, and didn't have to do anything special aside from keeping it on a humidity tray. He just happened to have access to a large south-facing window.


I first put my tropical in an old 30 gallon aquarium for the first time last winter. I have a layer of stones on the bottom and a glass hinged lid. After the first watering (not too much) it takes care of it self. I leave the hinged lid open for a few hours if the humidity seems too high; I give a watering every couple of weeks if needed. My tropicals have never done better. In the spring you do have to give the stones a good cleaning.
That's a really nice nepenthes setup. Especially the highland terrarium at the bottom. But as you can see its not a simple set-up, if you noticed there are ducts piped into the the tank for cooling the setup to about 50 deg at night and Im guessing one attached to a humidifier. Its one serious terrarium.

As the Nut have mentioned, it all depends on the trees your growing, imo, most tropical trees (but not all) will adopt to your growing conditions.

Here is a picture of my set-up. Its been running in Chicago cold and dry winters for years. Simple but it works.

Hope that helps.


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Very interesting, thanks Will!

Now, how effective would this way of growing be with, say, swamp loving trees like Bald Cypress?
I went out and bought a 10 gallon tank to experiment with this method. I need some aerial roots on my ficus. I set it in a bright window, filled the bottom with half an inch of water, then covered the top with plastic wrap. After 10 minutes the humidity gauge reads 65% and the temperature gauge reads 87 F. Not bad I suppose. I'll start placing the ficus in once the trial runs are over.
My brother - who used to sell scheffs planted into a drilled-out hole in lava rock sitting in non-draining trays - used to joke that you could grow scheffs immersed entirely in water, top to bottom. And I think he had done so, just to prove it. I don't think a picture of a scheff growing in an aquarium tells us much about it as a general technique, however. Other species will undoubtedly fail.

That being said, let's talk about growing aerial roots on a ficus in temperate climates. I've only seen it done once - in Robert Cho's tropical greenhouse near here. He can get ficus to do this by setting them for long periods on the cement floor, which is always moist from watering. The humidity down there, and the constant temps, recreate tropical conditions where ficus will perform this most noteworthy trick.

So, getting back to aquariums (is that the proper plural?), I wonder if such conditions could be created there to get aerials on ficuses (is that the proper plural?).

Otherwise, I agree with others here that they are best left to fish and lizards and such.

Thanks Will!

Just in case anyone isn't clear, I'm not filling the tank up all the way with water, or filling it at all, for that matter. At night I uncover it to allow flow of fresh air, before I leave for school in the morning I cover it back up again. Then, in the evening I turn the ultrasonic humidifier on. This is supposed to really help with the humidity in the tank.
You will kill a bald cypress in an aquarium. Just because they live in swampy areas doesn't mean they like to be in tropical conditions. A swamp is not the tropics.
After less than a week, I am beginning to see aerial roots forming on the potato mistakenly called a Ginseng Ficus.
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