FlytrapCare Carnivorous Plant Forums

I just finished putting together my highland terriaum, its just a rough concept version of what my larger one will be.

I made this one out of an old ikea file cabinet. First I gutted the thing and cut out a hole on top for the lights. Next I glued 1in thick pink foam to the sides for cold retention then covered the whole inside with 2 coats of drylok to seal any cracks and keep the moisture away from the foam and wood.

Inside the tank is an ultrasonic fogger for humidity and a waterproof fan connected to a radiator that will have cold water/antifreeze (I havent decided yet) from a chest freezer pumped though it when I need the temp to drop.

Tonight will be the first run, wish me luck. Should it fail to get the temps I need at least I will have a new terrarium for sundews!

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How did it work? Just curious since you mention a chest freezer, why not just use the chest freezer on a temp controlled outlet to turn it on to reach desired temps during day / evening ?

I wish I knew, im waiting on a new controller to arrive, the probe on the old one kicked the bucket.

This is eventually gonna used for a 90 gal tank, this small one is proof of concept.

The chest freezer has a ton more vertical space than it does horizontal, but they dont work right when placed on thier side. Using this meathod I can "store" a lot of cold energy for instant use.

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I thought you don't want to tilt compressors. I know when you buy a small refrigerator you are not supposed to turn it on for 24 hours if you have laid it on its side. So not sure laying the chest freezer on its side is so smart.
I suppose you could use some wire racks in it to have multiple levels, but for me I am hoping to use it for Nepenthes as they get too large for my regular cooler that I bring ice packs in each night

Yeah, I worded that funny. I am definitely not using it on its side.

The bottom footprint of the freezer is only 4x2 or something close to that, so once the plants start growing well and my collection inevitably expands i will run out of room very quick if i use it as the main growing area, plus i dont want the plants or pots accidentally touching the sides. Thats why im using it to pump out stored cold to the tank.

This method managed to get 20 degree night swings on my old 90 gal tank, which was made purely out of acrylic and wasnt sealed on the top very well. The new one will be insulated much better, so I can only imagine it will be more efficient.

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Ran it for the first time last night set for a temp of 55 degrees. I couldn't get the data off my temp logger for reason, so sorry no pretty graphs.

When I checked it last night before going to bed the temp had dropped from 78 to 55, and when I woke back up this morning the tank was still holding at 55 degrees. The temp in the chest freezer itself was 25 degrees last night and was 27 this morning, and I realized I didn't even have it set for the coldest temperature. Tank test #1, Success!

Dang! That looks fantastic. And congrats on the nighttime drops, 55 is quite an accomplishment!

What CPs are you planning to grow inside?

Thanks! I went through 4 or 5 different iterations of trying to cool larger tanks on a budget before landing on this one. Experience is a great teacher.

Im gonna grow any highland-ultra highland neps I can get my hands on, but im looking for the ones with bowl shaped pitchers like Jamban or Jacquelineae first-ish. There will also live sphagnum on the bottom to catch condensation from the radiator, in my old highland tank I found that sphag grew faster in it than any other method I tried. I dont know why but I wont argue with the results.

Over the past month I've been saving large empty liquid containers (milk jugs, 2-liter bottles, ect.) and filling them 3/4 of the way with water and putting them in the chest freezer to store more cold power. They are in the bottles as to not dilute down the antifreeze, if it is diluted too much it will freeze, defeating the whole purpose. Now that the chest freezer is mostly full and set to its coldest I figured it was time for another test. I still need to get some pipe insulation on the tubing which will make it more efficient, but in the grand scheme of things im not loosing too much from the tubing. I made it as short of a run from the freezer to the tank as possible, about 3 ft of exposed tubing in total. Not like last time when I drilled on the wrong side of the tank and had a total of 10ft of exposed tubing I had to insulate.


Test #2:
I set the controller for 45 degrees(10 degrees cooler that what I have been keeping it at) and let it do its thing. It dropped the temp in the terrarium from 81 to 45 in under 1 min, about 1 degree a second actually. It was able to keep that temp all night, which about 8-9 hours. Temp in the chest freezer was raised half a degree from night to morning. After seeing this I am very curious to find out what the absolute minimum temp this tank can reach is.
Test# 2 = Success!

3rd and probably final test will be minimum temp in terrarium and time held before temps start climbing again. I will probably do that one this afternoon, a whole bunch of highland neps are coming in very soon from a variety of different places, I need to get these tests out of the way now before they come in.

Just a quick update on the tank.

Absolute minimum temp was around 30 degrees and it stayed there for about 2.5hrs until starting to climb back up again.

The tank is still consistently hitting 55 degrees every night and holding there until morning, so on that front it is perfect. On a second note though, apparently the large temp difference between the outside and inside of the tank caused some expansion/contraction in the wood or the foam, Either way now there is a large gap on 2 of the foam seams that is letting moisture into the wood. I will try to repair it with some caulk and 3 more coats of drylock, but this version of the tank will definitely not be going full-scale, back to the drawing board I go.

For the next test tank I will build the entire interior out of 2" thick pink insulation foam, the outside frame will be made out of 2x4's just for stability and something to mount objects on. I think I may use box joints to join the panels of foam, seal all of those crevasses with caulk, foam sealant or maybe jointing compound (haven't decided yet), then do probably 5 coats of drylock on the inside and outside. Wish me luck! As always any insights, observations, or tips from fellow DIY'ers are always appreciated.