HCA: Hermit Crab Association

I just became the care taker of two crabs. I know nothing about caring for them. I bought a ten gallon tank and put a little bit of sand in. Maybe 2 inches worth. I know now that I need much more. Here are my questions.
What kind of tank heater should I use?
What is the false bottom floor?
Should the sand stay moist?
I know it is way to dry in there now and I will start making their lives better and more comfortable as soon as I can get the correct information. Thanks in advance for any advice.

Welcome! First, I highly suggest checking out the basic care guide if you haven't already. It can be found here http://www.hermitcrabassociation.com/ph ... hp?t=92457.
As far as Uths go I, and several others here recommend an Ultratherm UTH. I purchased mine at reptilebasics.com. A false bottom is an installation of cuplings, oftentimes pvc to prevent leaks in larger tanks because of all the moisture in our tanks. However, they are not necessary, and I chose to go without. That being said, yes moisture is good, you'll want sandcastle consistency throughout your sand. The basic care should help clear up a lot of questions.

Sent from my VS415PP using Tapatalk

Welcome aboard! Even though you may be a somewhat overwhelmed crabber now, believe me these little guys will grow on you fast!

A 10g is a good starter size tank, assuming the two crabs are no larger than golf balls. They grow fast in each molt when they're smallish crabs so you'll find yourself keeping an eye out for a larger tank within a year.

Be sure that the sand you're using is play sand (available at Home Depot/Lowe's for about $5 for a 50lb bag) and not the calci-sand sold in pet shops for use in hermit crab and reptile habitats. Calci-sand is potentially fatal for hermit crabs as it does not hold moisture properly and can solidify around a tunneling or molting crab, essentially suffocating him. Most crabbers use a mix of play sand and EcoEarth (coconut fiber) to create the substrate (5 parts sand to 1 part EcoEarth). It's a blend that retains the desired sandcastle consistency very well. The guideline link @Rawrgeous posted will detail how to mix the substrate, how deep it should be (6" minimum), as well as providing info on preparing dechlorinated freshwater and saltwater, what types of food to offer (almost everything we eat without spices and sauces), etc.

Heat and humidity are vital for hermit crabs as they are tropical and breathe through modified gills. Purple pinchers (PPs) are the most common type of pet crab and are probably the ones you have. They need consistent temperatures above 75 degrees and humidity of 80% or above. Using a UTH (undertank heat pad) is an easy way to establish safe parameters in the tank -- despite the name, a UTH is not placed under the tank but on the outside back of the tank above the top edge of the substrate. The rule of thumb is to buy the physically largest UTH that can fit on the back so, for a 10g tank, a 6x17 is ideal. The best brand is Ultratherm (most reliable, long-lasting, easy to mount/remove, low cost) which is only sold online at either ReptileBasics.com or BeanFarm.com. The 6x17 size is sold only by BeanFarm, if I remember correctly, and will cost under $20 + shipping.

To monitor heat and humidity, you'll want to get a thermometer/hygrometer combo. Pet stores sell analog varieties but digital models are more reliable, can be calibrated and are no more costly than the analog types. A popular unit is made by Acurite and can be found at Walmart for under $10: http://www.walmart.com/ip/AcuRite-Digit ... r/16888914

Reading through the Care Guides is the best way to get started but please feel free to ask any and all questions -- at one point, we were all where you are now .