HCA: Hermit Crab Association

Wondering what methods you all use to decrease mold growth in the tank? I have found mold growing on the moss frequently that I've had to throw them out and re-wash and boil shells:/. I am planning on adding both sw and fw baths soon and wondering if putting in air pumps would help reduce the mold? Advice appreciated!!

Air pumps increase humidity so you would, in theory, see an increase in mold. What are your humidity levels?

Ugh. Well this is weird. I just re-calibrated my zoomed hygrometer - I did check calibration when I first got it and it was spot on - and now it is reading 5 units lower?!?! Does this happen frequently? So now although it is reading my humidity to be at 80, it is really 75 :/. So maybe the pools with air pump will increase humidity? Also changed out the moss from petsmart healthy living ( I think is the brand?) to saphgum moss. what do u think? I'm kinda afraid to increase the humidity and have the mold start to grow like crazy

Also took out all shells, cleaned and boiled them. Took out a couple of the cholla sitting upright on substrate and replaced with 1 new one. Just added my pools with air pumps. Not sure what else I could do to prevent the mold... Temp is right on at 80 degrees.

Kermie16 wrote:Also took out all shells, cleaned and boiled them. Took out a couple of the cholla sitting upright on substrate and replaced with 1 new one. Just added my pools with air pumps. Not sure what else I could do to prevent the mold... Temp is right on at 80 degrees.

Where do you keep your tank? I've only had my crabbies for a few weeks, but I set up my 'tat a few weeks before that. I noticed the mold growth started when I moved mine into an area where it gets sun a few hours a day :/ Unfortunately I can't move it back right now (too cold!) so I've just resorting to buying new cholla and moss and soaked it in salt water and let it dry before putting it in. Seems to be alright so far

DarthCrabber wrote:

Kermie16 wrote:Also took out all shells, cleaned and boiled them. Took out a couple of the cholla sitting upright on substrate and replaced with 1 new one. Just added my pools with air pumps. Not sure what else I could do to prevent the mold... Temp is right on at 80 degrees.

Where do you keep your tank? I've only had my crabbies for a few weeks, but I set up my 'tat a few weeks before that. I noticed the mold growth started when I moved mine into an area where it gets sun a few hours a day :/ Unfortunately I can't move it back right now (too cold!) so I've just resorting to buying new cholla and moss and soaked it in salt water and let it dry before putting it in. Seems to be alright so far

Our tat is against the wall and although it does get natural light from adjacent Windows, there isn't any direct light on it. I do have a lot of condensation built up on the glass. I will try soaking everything in sw and letting them dry as u did! Thanks, DarthCrabber!!

Also vinegar is safe to use around the crabs, and will also kills mold, so maybe use vinegar and you might be able to salvage your cholla after a soak and scrubdown, and a few days to dry? Just a suggestion. Mold only bothers us, not the crabs.

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Don't put the tank right in front of a window; if it is in direct sun, it can quickly get too hot.

To prevent mold:

Clean out any old food sources lying around.

Soak any wood in half-strength MSW, then let dry COMPLETELY (for several days to a couple of weeks, depending upon size of wood and how dry the air is where you are) before putting in tank.

Do not put any wood directly on moist substrate or allow it to directly touch the glass tank walls (which often have condensation on them). Brace it on a big clam shell or something plastic; hang it from zip ties; get creative.

When moistening moss for a moss pit, use half-strength to 1/3 strength MSW for the first moistening (after that, use fresh water).

Get a small FAN for your tank. Moving air is good for several reasons, but helping to prevent mold is a big one. We used to have constant mold problems, until I put fans in the tanks. After that, the only mold I have seen is in one corner where I realized the way the decor was set up, there was little to no air flow back there. Changed the set up and no more mold. I highly recommend putting the fan on a timer, so you can regulate how much time it is on and off, because it will bring down humidity some while it is on.

In conjunction with a fan, I highly recommend making your water sources into bubble pools. They are great for humidity, they make sure you get fresh, humidified air pumped into the tank at substrate level on a regular basis, and they keep your water sources fresher for longer. Putting the air pump for your bubble pools on a separate timer allows you to fine-tune the humidity between the bubble pools and the fan.

DragonsFly wrote:Don't put the tank right in front of a window; if it is in direct sun, it can quickly get too hot.

To prevent mold:

Clean out any old food sources lying around.

Soak any wood in half-strength MSW, then let dry COMPLETELY (for several days to a couple of weeks, depending upon size of wood and how dry the air is where you are) before putting in tank.

"MSW"? I'm new to keeping hermit crabs and I'm not sure what that is. I'm guessing something salt water?

Thanks, guys!!! Really appreciate all of the advice!! I will give them all a try. DragonsFly, I did notice u had posted something similar before about the fan so I went ahead and ordered myself a little 5 inch fan - but it is battery run:/. Didn't think about putting it on a timer. Would it be better to run the fan while the bubble pool is on or on the off times? I will look for another fan in the meantime. Thanks again!!

Hey Vidikron! I'm also new to crabbing so, welcome!! Anyone please correct me if I'm wrong but I believe MSW stands for marine salt water.

Kermie16 wrote:Hey Vidikron! I'm also new to crabbing so, welcome!! Anyone please correct me if I'm wrong but I believe MSW stands for marine salt water.

Ahh... That make sense.

It will depend on the individual tank and whether it tends to run high in humidity or low. If it tends to run low, you will want the fan to run only while the bubble pools are going, and let the bubble pools go a little (or a lot) longer after the fan goes off to replenish the humidity. If it tends to run too high in humidity, run the fan while the bubble pools are going, then let the fan run for a while after they stop to bring it down some. I'm a big fan of timers, too--I have my day lights on a timer (the night lamps are on continuously, for a constant source of heat), bubble pools/fountain on another, and fan on a third. It sounds like a lot, but they are pretty cheap at your local Lowe's or similar hardware spot, and they just make everything so much easier. If you find something (temp or humidity) is a bit off, you just quickly adjust the little spacers to make something run more or less, and it will keep the new "schedule" until you decide to change it again.

Sorry, Vidikron, MSW is short for "Marine Salt Water"--the salt water source you should be providing your crabs should be made with the same kind of stuff that is used to make salt water for salt water fish, like Instant Ocean or Oceanic. I don't like to just say "salt water," because sometimes people have mistakenly thought they could just mix some table salt (or even table sea salt) in with the fresh water and that would be okay. You really need a Marine Salt Water mix.

Ok! Have a different fan coming my way with a plug in! I have plenty of extra timers, so I will put the bubblers and, when it comes, the fan, and give it a go! Thank you for all of your advice, DragonsFly!! Sooooo less stressful with the support and help from the HCA members

Yes, there is nothing like this place. I know our first two rescues, coming to us with us utterly unprepared, would surely have died without the knowledge and patience of the long-term crabbers here who walked me through that really, really steep learning curve of how to keep these animals alive in captivity. It's the least I can do to pay a little of that forward (although it should be noted that there is ALWAYS more to learn; after only about five years of dealing with them, I sure don't think of myself as a "long-term crabber" yet!).