What is the maximum number of crabs for a 20 gallon?

crabby33 · Post by **crabby33** » Sat Jul 23, 2016 4:59 pm

I currently have 2 crabs, a medium and a large in a 20 gallon tank. I want to get one or two more. I know Purple Pinchers are generally fine with being overcrowded after reading the care files here. The amount of space for large crabs in a 20 gallon recommended here is 5.5 gallons per crab. The Hermit Crab Owners FB page promotes 10 gallons per crab while you guys promote 5.5 gallons per crab. So how many more crabs could I put in my 20 gallon?

MsWorld · Post by **MsWorld** » Sat Jul 23, 2016 6:24 pm

It really depends on the size of the crab but you have to remember the crabs will grow and will require more room. With your size crab I say you are at full capacity in a 20g.

I don't know where you read on here that over crowding is fine because over crowding is not fine. It leads to all kinds of problems. Shell fights, picking on the weak ones, shoving, pushing, rolling, fighting over food. Not to mention the biggest over crowded problem, when they go down for a molt, you would have them being dug up.

With the size crabs you have, I personally would not get anymore. That's just my opinion.

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crabby33 · Post by **crabby33** » Sat Jul 23, 2016 6:32 pm

I thought I read that here but maybe I read it somewhere else. I'm trying to find where I read it.

Post by **aussieJJDude** » Sun Jul 24, 2016 4:06 am

Maybe you might of got confused with PP's are generally peaceful and as a consequence, overcrowding issues isn't that apparent?

Care guide here on the careguide it states, "PPs also do well in very large communities." Which is great, providing you have a large tank. But would love to see where you read that.
Ahh, I found where you might of seen it: tank stocking guide here...
"Some Es and Exotics may be too crowded by this guideline, while Purple Pinchers are normally fine with being more crowded".... Its meant to be a comparison between the exotics and the PP's.

As much as I love the guide, I know it don't work for me. According to the guide I could have up to 20 crabs in my tank!

I personally consider it too small for even my colony of 8!

I personally prefer the "floor space method", where its not the total gallonage that comes into play, but the amount of surface area. The bigger the surface area, the more crabbies the tank could - technically - hold.
Which also brings me to my next point, everyone has different options as we have all had different experiences. I seen people that recommend no less than 20g per crab, others 10/20g for the first crab and every crab after that is 5g. Others just cram in crabbies until they feel like they are at their max. The most important decision to make is where do you see yourself going: are you able to upgrade the tank as the crabs grow? The more crabs you have, the quicker the tank will turn overcrowded leaving you to upgrade or move crabs into new tanks.

Giner13 · Post by **Giner13** » Sun Jul 24, 2016 10:14 am

I currently upgraded to a new 15gal...have 2 crabs, although one is still in the old tank molting away!! I was excited about the new 15gal with more floor space as @aussieJJDude mentioned. More room to roam!

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cap7 · Post by **cap7** » Sun Jul 24, 2016 11:12 am

I'm a crabber newbie, but I was surprised how 2 crabs could trash a 10 gallon tank. Depth of substrate is so important but surface area is too. Second levels help.
I upgraded to a 29 gal for 4 crabs, one is still in 10 gallon, I hope molting. I can see why bigger is better, and why we keep looking for that bigger tank.
My new tank is already packed after putting in all that is needed. The crabs are doing well, but I can't see having anymore than 5 in this tank.
I need an 'E' for a buddy. Anyone?

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cap7 · Post by **cap7** » Sun Jul 24, 2016 11:15 am

Mine are all smalls btw

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soilentgringa · Post by **soilentgringa** » Wed Jul 27, 2016 6:20 am

I'm not going to get into a debate over which crab group suggests what, and the differences between their care requirements and ours.

I will say that HCO recommends 10 gallons per crab, if you never intend on upgrading your tanks.

Here, we feel that not everyone is going to rush right out and drop hundreds of dollars on a pet that they were told: 1. It's easy to care for and can just live in this small plastic box. 2. Can live off pellets and will probably die within 6 months to a year.

Many people drop like five to ten bucks per crab and spend less than $50 on their entire setup. It's usually a shocker when they find out that the crabs need much, much more than what they were led to believe.

We recommend that you upgrade as you go and use your best judgement. Are your crabs dying in molt attacks? Are they super aggressive? Are you packing them in like sardines?

Different groups are going to have different recommendations. That's just the way it is. My suggestion is to read all the material at hand and use common sense. Research on your own and check all the facts presented.

The one thing that I will say about this forum is that it has been around for a very long time. As far as I know this is one of the longest running crab groups in existence. Many of the veteran crabbers and founders of this group, like @JediMasterThrash, have been crabbing for decades. They've seen all of the advancements, rumors, myths, and more in hermit crab husbandry. Crabbing is constantly evolving as we learn more and more about the coenobita species in general.

crabby33 · Post by **crabby33** » Wed Jul 27, 2016 1:16 pm

I have had no problems with aggression and shell fights with the two crabs that I have. I also agree that not everyone is going to drop hundreds of dollars to upgrade. I'm one of those people. A 29 gallon runs upwards to $100 or more and I just don't have that kind of money. My mom and I have agreed that five crabs is too many for a 20 gallon but the maximum number I can have in there is three. I still plan on buying one more for my crabitat and that's it.

crabby33 · Post by **crabby33** » Wed Jul 27, 2016 1:19 pm

Plus, I have had my two crabs for two years. That shows you how much the pet stores are in the wrong. I did all the research on my own and found that a) sand/Eco Earth is a healthier substrate and b) pellets are not good for them, kind of like eating junk food is not healthy for people.

crabby33 · Post by **crabby33** » Wed Jul 27, 2016 1:21 pm

And to answer your first question, no, my crabs are not dying in molt attacks.

soilentgringa · Post by **soilentgringa** » Wed Jul 27, 2016 2:35 pm

They where rhetorical questions, lol.

And I don't know where you live that a 29 gallon is over $100(!) Petco has a dollar per gallon sale several times a year; it's on right now I believe.
Craigslist also usually has used tanks too at decent prices, so check CL and thrift stores.

crabby33 · Post by **crabby33** » Fri Jul 29, 2016 10:21 am

I live in Dallas. But I'm at my mom's house in Ennis right now recovering from surgery. I have a very small apartment and my parents have always told me: conform to the size of my apartment. So, small tank. Small apartment. My parents think a 29 Gallon tank is too big for my small apartment and I have to listen to what my mom says. She'll think I'm buying a bigger tank just to buy a bigger tank.

crabby33 · Post by **crabby33** » Fri Jul 29, 2016 10:22 am

To them, it's an impulse buy and I'm being taught not to buy on impulse.

soilentgringa · Post by **soilentgringa** » Wed Aug 03, 2016 10:21 am

crabby33 wrote:I live in Dallas. But I'm at my mom's house in Ennis right now recovering from surgery. I have a very small apartment and my parents have always told me: conform to the size of my apartment. So, small tank. Small apartment. My parents think a 29 Gallon tank is too big for my small apartment and I have to listen to what my mom says. She'll think I'm buying a bigger tank just to buy a bigger tank.

Is there a reason why your parents have a say in how you set up or decorate your apartment? You are free to answer via PM if you don't want to post this publicly, but I am almost sure I have seen you discussing this situation in another group.

Also, have you encouraged your mother to read the care information or join the groups so that she can understand that we don't make these suggestions lightly?

I am not in any way trying to be offensive; I realize that different people have different dynamics with their family. My mother can be controlling and it was quite the battle to get her to understand that I'm an adult, I pay my own bills, live in my own home, and she has no say over what happens in it.

HCA: Hermit Crab Association