The $10 Hermit Crab Tank Humifier




Hermit crabs, super fun, easy pet right? Well, if your like me, you spoil everything you ever deem your pet. In which case, I couldn't keep my hermie tank's humidity above 50%. I guess keeping my room a constant 75 tends to dry out the air. So I went to the pet shop to see if they had a humidifier for the tank, and they had nice expensive humidifiers that seemed to puff out mist instead of just keeping the humidity up. So brainstorming in the pet store (and a bit more at home) I came up with this.

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Step 1: Things You Will Need

You can get EVERYTHING and I mean everything at wal-mart.

1. Aquarium Pump - I got mine for $15 but I paid extra for quiet since it's located in my bedroom. You can get an aquarium pump for $7
2. Aquarium Hose - $1
3. Air Stone - $.50
4. Jar with plastic top $1

Items in your home you will need (or you will have to pick them up)

Hot glue gun
glue sticks
drill or something to poke pencil sized holes in your lid

Step 2: Assembly

1. Drill 2 holes in the top of the lid. Just a smidge wider than the aquarium hose.

2. Feed hose in to the lid as shown in the picture below.

3. Cut the hose into 2 sections. On mine, I had one shorter and one longer as to accommodate placement of the humidifier and tank.

4. Attach air stone to the shorter of the two pieces inside the lid. making sure that the air stone hose is long enough that when the lid is sealed the stone is about 1/4" from the bottom of the jar.

5. Glue around the hose to keep them in and make it air tight. This is important.

6. Attach hose connected to air stone to aquarium pump.

Step 3: Plug, Pump and Ready to Go!

Feed unadorned hose into tank, fill with water, close lid and plug in.

The bubbles cause the air in the jar to become moist, then the moist air is pumped directly into the tank! Simple and works well!

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62 Discussions


10 years ago on Step 1

I would just want to say that you got the prices WRONG! yur instructables is perfect but the air stone is $1.50 the jar is $1.85 and the hoze is $1.50 the pump is the only one with the correct price...I put the humidifier together and my hermit crab is very happy and is walking around more! than you very much! p.s. i named my crab joe because i got him from joes crab shack! lol

7 replies

Reply 3 days ago

im going to get the airstone and container today to make the humidifier.i looked and they have small rectangle ones and bigger round one .which one should i get .not sure if it has to be big !


Reply 4 years ago on Introduction

@halo99 - No where in your thought process did you consider that PRICES VARY FROM STATE TO STATE ? OR even where you buy them? walmart vs. petco for example !!?


Reply 9 years ago on Step 1

joes crab shack? i didn't know they sold hermies there! You shuld get your little guy a partner though.

so with the 2 hoses, one is connected to the air stone one end and the other end is connected to the pump.. but why is there 2 and what is the second one connected to. do oyu put the jar in the tank?

3 replies

The smaller of the 2 hoses, goes from pump, into the lid and that piece has the air stone connected to it. All one short piece. It introduces the air, softly to the water. The second, length of the 2 hoses, goes from inside lid, to the tank, that piece is as long as you need it to be, to reach your tank, TOP. it should go inside your tank rather toward the top to then blow in cool, moist air. Try to keep the food on the other side of the tank so it will not become to moist to fast and rot. Do not place this hose into the water, your not looking for another bubbler. This whole process should help with the humidity in the tank, if your lid is solid and not a wire grate it will. personally just have a salt water pool with a bubbler in that directly and the crabs go swimming and it keeps the moister and there happiness up also. I have my fresh water set up as a fountain. My crabs live in a mansion/castle.

gam4crabCrabby Witch

Reply 5 days ago

do ya have a pic or explain how ya made ya fresh water fountain .sorry i wasnt understanding what ya did .
i have had my hermit crab for almost 8 years .about 4-5 months ago i got a huge aquaruim tank and having a hard time keeping the humidity to stay high .im always spraying in it and have a wet towel on top of aquarium.


1 year ago

I'm just going to go ahead and assume your crabs died already right? There is sooo much misinformation (especially from pet stores) but I've finally found somewhere with as close to hermit crab experts as there are. If anyone here has hermit crabs in an enclosure of any kind that isn't completely sealed, please FOR THE LOVE OF YOUR CRABS make sure you get it completely sealed, they have modified gills so they need at least 80% humidity to even breathe. Next, check out the files on they will tell you any and all adjustments you need to make to ensure your crabs aren't in danger. Hermit crabs are in no way an easy or cheap pet, please don't enter into the crab world lightly.

1 reply

8 years ago on Step 3

you should get a sealed aquarium or rap that cage in suran rap to lock in humidity

2 replies

4 years ago

Well it was kinda a high pitch chirping sound. I thought it was my dog whining so im still not quite sure if it was really them or not but it came from that direction and I was too afraid to get up and look in case they stopped.

2 replies

Reply 2 years ago

hermies chrip to establish dominance, mate and just socialize. it is kind of odd but it means they are happy!


Reply 1 year ago

it is a distress sound, if you're hearing them chirp, something is very wrong