Humidity Help! I added bubblers and my humidity dropped!

This is where you discuss the conditions of your crabitat -- temperature, humidity, substrate, decorating, etc.
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Humidity Help! I added bubblers and my humidity dropped!

Post by CrabbyPants1022 » Thu Jul 02, 2020 6:52 am

1. What kind of substrate is used in your tank and how deep is it?
I have about a 5:1 mix of playsand and coconut fiber brick, sandcastle consistency. It's about 7 inches deep.

2. Do you have gauges in the tank to measure temperature and humidity? If so, where are they located and what temperature and humidity do they usually read?
I have a small circular gauge that measures temp and humidity, located above the water dishes on the side of the tank. The temp reads about 75-80% and the humidity is currently reading 65, which is why I'm posting. :(

3. Is a heat source used in the tank? If so, what?
I have an UTH, forget what brand, located on the back side of the tank.

4. What types of water are available (fresh or salt) and how is the water treated (what brands of dechlorinator or salt mix and what ratio is used to mix it)?
I have both fresh and salt water located in deep pools. Fresh is dechlorinated, I forget what brand I'm using, I'm not currently home to look. And the salt water is made with dechlorinated water and instant ocean.

5. What kinds of food do you feed and how often is it replaced?
I feed fresh food that changes daily. Usually always have some type of protein (chicken, shrimp tails, sardines), veggie (spinach, cooked carrot, seaweed), fruit (blueberries or bananas usually), and nut (unsalted pistachios, almonds, peanuts) as well eggshells or honey occasionally. I also have a cuttlebone in there.

6. How long have you had the crab and what species is it, if known?
Purple pinchers. Two I've had for 6 months and the other two I acquired recently, about a month ago.

7. Has your crab molted, and how long ago did it happen?
One molted a couple weeks ago. One is down now and has been for a few days, possibly molting.

8. What type of housing are the crabs kept in, what size is it and what kind of lid is on the housing?
20 gallon glass tank with a screen lid. The lid is taped over to cover the holes and then I have a glass lid that is meant for a 30 or 50 gallon tank sitting on top of that (doesnt fit my current tank but put it on top just to try to keep the humidity in)

9. How many crabs are in the tank and about how large are they?
Four. One is large, the rest are medium sized.

10. How many extra shells are usually kept in the tank, if any?
Over 15.

11. Have there been any fumes or chemicals near the crabitat recently?

12. How often do you clean the tank and how?
I change food every day and spot clean as needed. So far have not had to do a deep clean of the tank.

13. Are sponges used in the water dish? If so, how are they cleaned?

14. Has anything new been added to your crabitat recently?
A seagrass hammock with suction cups, pillow moss, and air stones.

15. Is there any other information you would like to share that might be helpful (anything that is regularly part of your crab care, playtime, bathing, etc.)?

Described below.

16. Please describe the emergency situation in detail.
Up until now, the humidity in the tank has always usually read 70%. In an attempt to increase the humidity a little bit, I added a moss pit made with pillow moss and air stones in the water dishes. While adding those, I also redid the tank a little. I added a seagrass hammock above the water dishes, and rearranged their climbing wall a little. This was done about a week ago. And ever since I did that, the humidity actually dropped! What once read 70-75% now usually reads 65%! I thought these things would help the humidity, not hinder it. I spray the tank daily after cleaning their food and that raises the humidity to about 70% max. I don't want to keep spraying as I know that's not good. I'm just not sure what else to do. I even tried turning off the air stones to see if it would go back to how it was before and it doesn't, that makes it even worse. I calibrated the hydrometer and it is accurate. I'm not sure where I went wrong or what else I can do. Is it possible the seagrass hammock is affecting its reading? The gauge is located on the wall of the tank above the hammock. Please help!

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Re: Humidity Help! I added bubblers and my humidity dropped!

Post by GotButterflies » Thu Jul 02, 2020 10:53 am

A few notes:

The hammock is potentially absorbing some of the moisture.

Did you moisten the moss before you put it in? That would have absorbed some of the moisture as well.

I would avoid spraying the tank. That can lead to flooding.

How deep are your pools?

The main thing that probably hurts your tank is lifting your lid to change your food, or going in it. It will reset humidity all over again. Also, the bigger the tank, and the deeper the substrate, the easier it is to maintain humidity. I'll address your other questions now.

As far as temp - IMO, temp should be 80-85 you will have more active crabs. I know you are working on your humidity. I keep my humidity at 99%. I do recommend digital hygrometers. Here is the type I use: ... 184&sr=8-2

Heating: IMO it would be better if you could get your heat up to at least 80. You can try to insulate around your heat pad with aluminum foil (shiny part facing the crabitat), then cardboard. Don't insulate over your heating pad if it is a zoomed. If doing the insulation doesn't raise your temperature, you might want to consider getting a better heater. Most of us use ultratherms. They are great heaters. or sells them.

Are you using a light? That would cause your humidity to evaporate. I don't like heat lamps due to that fact. I use UVB strip lights.

With mesh lids you can cover them in Press-N-Seal, or cut open gallon sized Ziploc bags and tape them to the outside with packaging tape to help keep the humidity in the tank.

Hermit crabs can eat a lot of the same things that we eat. Just check to make sure the item is on the safe list. Foods should be organic when possible. Hermit crabs are sensitive to pesticides and fertilizers.
You also want to provide one or more calcium sources at a time. Examples would be Cuttlebone, Organic Eggshell, Oyster Shell, Lobster Exo, Shrimp Exo.
Make sure you cover all aspects of food pyramid :)
Safe food list: ... 25&t=92557
Unsafe food list: ... 25&t=92556
Food pyramid: ... 25&t=92554

The HCA recommends 3-5 shells per hermit crab. I personally recommend more. It never hurts to have more :) There are incorrect shells to buy. Here is the shell guide: ... 24&t=92552
Truly blessed to have incredible creatures, wonderful friends and my amazing family in my life!! I'm very thankful & grateful for all of them!

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