20 gallon tank

[Bob23]

How many crabs can I house in a 10 gallon, 20 gallon? 30 gallon tank?

Also how much would it cost to own hermit crabs. I did my research for like 2 hours and know all the necessities, heat, humidity, 6" soil, etc.

Thank you!

[wodesorel]

There is no great answer for how many in a certain sized tank, because they will keep growing and the bigger they get the more space they need. A full grown crab needs at least 12 inches of substrate and a tank 4 feet long by 18 inches wide. The really big problem is that there is no perfect way to know when they will get to that point, as they all grow at different rates. It could be one year or it could be 15! The smaller the crabs, the longer they can live in a smaller tank. Ideally dime or nickel sized will give you the longest. Ping pong ball sized can triple in size in one molt and then you may end up with more crab than you were planning for.

Not to ignore your questions, two smaller crabs could possibly be okay in a 10 gallon for a few years, in a 20 for a couple more years than that, and in a 30 even longer. If you know that you could get a larger tank whenever needed then you could certainly add a few more crabs safely.

The larger the tank, the more space you'll have for substrate and climbing and decor. 10s are tight, and not much fun to decorate. You may have trouble fitting the basics in, let alone anything else you like.

For the easiest tank to maintain, an ultratherm UTH for heating is a great idea. That would be dependant on tank size but they generally run $30-$40. It reallt is a set it and forget it heating method, and it doesn't need to replaced regularly like light bulbs do.

A tank can be anything from brand new (a 30 gallon and a lid for the tank at the $1 a gallon sale at Petco would be around $55) or used (in which case you may find the same thing in local classifieds for between $0 and $30), to a plastic storage box ($10).

Playsand is cheap, you'd need about one bag per 10 gallons and locally I pay $4 a bag.

Instant Ocean is under $10 for a box that will last you all year.

A good dechlor I think is under $5 for a small bottle. (I have a lot of pets and buy the big bottles.) And that should last for years as well. We like Seachem Prime around here since it both dechlors and rwmoved heavy metals.

Everything else is whatever you want to buy specially for them. Water bowls can be margerine containers, food can come completely from your own diet, you can get sticks outside for them to climb on, etc. Or you can get silly and buy whatever you like to make their tank special. Totally optional and the crabs won't mind either way.

[curlysister]

I have two crabs that I have had for 7 1/2 years. I started with a 10 gallon tank that they came in (got the tank and the crabs for $20 off a local swap and shop). They basically had nothing else with them, so it cost me for sand, EE, a couple of bowls and pools, cholla for climbing, a small UTH, and a hidey hut. I order food and Instant Ocean from the Hermit Crab Patch, and shells from Naples Sea Shells. Then a couple of years later, I traded my 10 gallon for a 20 gallon plus a donation to the charity that was selling tanks. Of course I needed more sand, more EE, bigger pools, a bigger UTH, more things to climb, and another hidey hut. More food and larger shells as they grew. Last year someone in town was getting rid of her hermit crab supplies because hers all died, so she gave me her 50 gallon with a plexi-glass lid. More sand, more EE, more decorations, larger UTH, etc. I had to get a different table to put it on, because I was worried that the weight of the tank with all the wet sand would break the one it was on ($50 on the local swap and shop for the table). One of my crabs is large to jumbo now, and his shells are about $20 each. The smaller shells are $10-12 each.

[crabby33]

I have one crab that grew from a 7/8" opening to a 1 1/4" opening, skipping the 1 inch opening completely. I also have a second crab that is molting and he could do the same thing.

[piratetoothgir]

You can keep two in a 10 gallon for a while, but after the first few molts, they get too big.
Two can go a while in a 20 with no problems!

[Hermiesguardian]

I have one crab that grew from a 7/8" opening to a 1 1/4" opening, skipping the 1 inch opening completely. I also have a second crab that is molting and he could do the same thing.

I guess the only way really to tell exactly what size opening they need is to provide it and see if they choose it, right? It's really hard to know what sizes to get. I have 6 crabs so that's a lot of shells I need to provide.

[AwesomeHermit]

You can keep two in a 10 gallon for a while, but after the first few molts, they get too big.
Two can go a while in a 20 with no problems!

Depending on the size of the crab, but overall I agree.