The information in this article is somewhat outdated in that we generally no longer do scheduled deep cleanings. If your tank is set up properly it can be self cleaning, self sustaining. However if you have a flood or a bacteria outbreak or some other emergency situation you may find this information beneficial.
written by Michele Stephens
You’ve set up the perfect crabitat, the hermit crabs have been roaming happily about the place for weeks, even months. You change the water and the food but now, the substrate just isn’t looking as fresh as it use to and you suspect that it might be time to do a deep clean (a total tank teardown). Crabs in the wild are in an ever-changing environment that is cleansed by the elements, like rain and running water, sun and wind. Our crabs don’t get that in their tank so it’s up to us to do it for them. Okay, how do we do it? Well first you need to decide if it’s the right time. There are several factors that you need to consider before deep cleaning the tank.
- How long has it been? Generally you can expect your tank to need a deep clean every 3-5 months depending on how crowded it is in there.
- What is the status of the colony? Is everyone up? Is there anyone you haven’t seen in awhile? Are there any new additions? You want to try to time it so that you do the deep clean with as many crabs topside as possible.
- Emergency deep clean. Sometimes you may have to do a deep clean earlier because of emergency circumstances. A major mold outbreak, mites, or ants would be good examples. Those types of deep cleans require some special directions that I will not cover here.
Once you’ve decided that you’re ready for a deep clean you need to get some supplies. It really depends on your tank and your preferences, but most of the following supplies apply to all deep cleans.
- Lots of salt water (the same kind you give your hermit crabs to drink).
- Substrate – if you are replacing yours. Some people prefer to remove, sift, and bake theirs but I prefer to fully replace mine.
- A cookie sheet
- Some bowls, the bigger the better
- Vinegar and a couple of lemons
- Paper towels
- garbage or big bin for holding the substrate in as you remove it
- an ISO or isolation unit
What you can do the night before
- I usually am short on time the day of the deep clean so I like to get my work down as early as possible. There are some things you can do the night before to save you time on deep clean day.
- Prepare your ISO tank. Make sure your humidity and temperature are within range. Especially if you are baking the sand/FB and they will be in there for a prolonged period of time. I’ve found that some Fiber Bedding reconstituted with warm water boost temp and humidity quickly.
- If you are adding any new climbing elements or other toys, caves, pools, you can sterilize them now. With plastic and resin items I wash in a straight vinegar spray followed by peroxide before rinsing. Wood and cocohuts are soaked in salt water and baked at 250 for 20 minutes. Netting is soaked in salt water and microwaved in a glass bowl for 2 minutes.
- If you are using fiber bedding you can hydrate it the night before so it’s ready, if you like to bake your sand, this is a nice time to do that too. (if you’re adding new)
- One of my favorite things to do the night before the deep clean is to have the “Grand Stinky Feast”. Pull out your grosses, stinkiest foods and line them up. Shrimp, tuna, silversides, you name it. You don’t have to worry about where it will end up because you’ll be cleaning it all out tomorrow!
- Then while you watch them eating the eyeballs out of your silversides you can stare at the tank and plan the new layout you’re going to execute perfectly tomorrow.
Tearing the Tank Down
First you will want to remove the climbing items and nets and sterilize them the same way that you did the new items the day before by soaking and baking. As you remove each item check it carefully for mold and for clinging crabbies. Items with mold need to be treated more aggressively than items that are mold-free. When you have your climbing items removed and soaking your tank will be empty except for the substrate. Grab two bowls. One bowl for shells, filled with salt water, one to give your crabs a bath in, filled with fresh water. You should also have an isolation unit or holding tank ready for them to wait in while you clean out the tank. As you remove “empty” shells put them in the salt water. A shell should always be treated as though there is a crab in it. Placing it in the water will force a hiding crab to emerge if it’s very small in the shell. Turn the shells over and over in the water to get the water all the way to the back. You’ll know you’ve gotten it completely full when no more bubbles come out and the shell no longer floats.
Once the “empty shells” are dealt with remove any surface crabs, give them a quick bath and put them in the holding tank. I use a 10 gallon aquarium for mine. You should have a good idea of how many crabs that you have. During deep cleans I like to photograph each of my crabs to chart their progress. The next step is the most delicate and the most nerve wracking of the whole process. During this particular deep clean I had 9 of my 15 crabs down. I was sure that many of them were just buried (maybe someone told them my plan) but I also knew that odds were very good that a few were molting. To prepare for this possibility I set up my 3 gallon ISO.
Grab an empty garbage can and line it with a new garbage bag. Starting with one corner carefully remove the sand one handful at a time. I usually empty each handful into a large plastic cup, sifting each one, then pour it into the garbage bag, sifting again. I cannot stress enough how important it is not to rush this part of the deep clean. Once you have a small area cleaned down to the bottom of the tank slowly widen the circle a little at a time. You want to find the buried crab from the side rather than the top, that way if their cave collapses it is only for a very short time. As you come across your buried crab assess whether or not he is molting. Obviously the presence of an exoskeleton will indicated a freshly molted crab but other signs will let you know where your crab is in the process. A pale crab with sharpened nail tips who withdraws far into the shell may indicate a freshly molted crab. Usually these guys are safe to return to the regular group but you can isolate them for a few days to be sure. If you find a crab in mid-molt carefully remove them and their exo to the isolation tank. Place a cocohut over them or nestle them into some moss. Put the ISO in a low traffic area and keep an eye on them, most crabs do quite well, even when disturbed as long as its not repeatedly.
Once all of your crabs have been collected do a head count. Even with this double sifting one of my crabs made it through the system and I had to get her out of the bag of sand. Your next job is to clean the tank. You can do this a number of ways. High concentration salt water, vinegar, or lemon juice are all good alternatives. My favorite method is to cut a lemon in half and use it to scrub down the glass. To minimize scratches from sand take a damp paper towel and carefully push all sand to the bottom of the tank. Whatever method you use, rinse the tank until the smell is no longer detected. This is when your advanced preparation pays off. Place your substrate in the tank. Remember that substrate should be twice as deep your biggest crab. I use damp substrate and I wet it in the bottom of the tank and mix it together as I add it. I slope mine toward the back of the tank so that it is almost twice as deep in the back as it is in the front.
Finally, the fun part, arrange your tank however you want. Try something new! Your crabs like variety and change, it keeps them active and curious. Once you’ve got your crabitat set up the way you want, add your empty shells and your crabs. Grab your camera. This is the best time to take pictures of your crabs, they are always at their most active when exploring their new territory.