HCA: Hermit Crab Association

Just came home from a week out of town and am finding mold all over my bamboo and grapevine, small fuzz that was barely noticeable... until I started noticing it!

I'll describe the situation and ask questions at the end:

Tank is my new 65g, has been running for exactly a month. Temp/humidity are consistently 81F/80%. Only the msw pool has a bubbler, which runs for a half hour once every 3 hours during the day. **Edit: forgot to add that I have an LED light rated for planted tanks (mung bean and chia sprouts LOVE it).

The bamboo is a large tube/tunnel, open on both ends with large holes on both long sides, and it is suspended above the msw pool on one short end of the tank. The msw pool is the only one with a bubbler in it, and I typically have overspray onto the glass and all nearby structures/decor. Though the actual spray doesn't reach as high as the tube, the bamboo appears to be suffering water damage. Mold is growing on all the cut edges of the bamboo. I have a cluster of bamboo sticks next to the msw pool but can't tell if it has mold (I'm pulling it out to check).

A large piece of grapevine runs through the middle third of the tank. The parts that are on the sub are actually siliconed to small pieces of plexi, with pebbles and coarse oyster shell siliconed over them (so it's plexi touching the sub). Tiny white fuzz is over maybe 25% of the grapevine, and there appear to be some dark (greenish?) spots as well.

The fishnet hanging over the msw pool is always soaking wet in msw. I think I see some fuzzy spots--which could just be frayed net--I'm going to look at it more closely when I open up the tank to deal with all this later today.

When we were building the tank, all wood was soaked in half strength msw overnight and then dried for several days before going into the tank. The water that is spraying out of the pool is full strength msw.

Questions:
Do you get overspray from your bubblers? Does it cause problems (mold, overly wet sub, etc.)? What can I do to limit the spray (I have a tiny pump with the smallest airstone I could find)? I was actually about to add a splitter and start bubbling my fw pool, but now I'm hesitant in case it's going to cause problems with the cholla and coco hut nearby.

How do I remove the mold from the bamboo and grapevine? Soaking in half-strength msw didn't prevent it, so I'm not inclined to soak again. I've read I can scrub it off with a marine salt paste. Do I need to bake the wood?

How can I prevent this happening again without re-designing my entire tank layout? Or should I just bite the bullet and relocate the bamboo away from the msw (or relocate the pool away from everything else)? The grapevine isn't getting wet, though, and it's also molding. I'm putting a fan in asap (it shipped while I was out of town), but it probably won't cover the entire tank area. Should I point it towards the msw pool?

My 10g and 20g all held 80F/80% without mold ever appearing on anything but day-old fruit, so this is new for me. I even had oak branches for climbing and eating in those tanks for months, but in the new tank a small stick in the leaf litter dish grows mold in a day and a half.

Wish I knew what to tell you, but don't have a bubbler myself. Hope someone chimes in that does! Sounds like a heck of a problem!!


Sent from my iPhone using Tapatalk

What you need are check valves / air valves. I bought a package at PetSmart that had both splitters and air valves / check valves in it. We split our bubblers with a tiny air pump and tiny air stones. With the valves you can control the flow/speed and so far we have had no mold problems.


Sent from my iPhone using Tapatalk

I think that entire package with the splitters and valves was around 5.00 but don't quote me. I can take a picture of the valves and splitters if you like.


Sent from my iPhone using Tapatalk

The hubs came home and added his analytical mind to the mix. His first thought was to stop using the bubbler until we have a solution, duh! Bubbler unplugged. Frantic amateur crabber calmed down.

MsWorld wrote:What you need are check valves / air valves... With the valves you can control the flow/speed and so far we have had no mold problems.

Fantastic, thank you. It's going on the list for next trip to Petsmart (we were just there last night, too; d'oh!).

We're about to open up the tank and pull out everything that looks affected. Plan is to scrub down with marine salt paste and dry out in the oven (hopefully the plexi won't melt). While they're drying we'll figure out where to place the fan(s), and decide if we're going to relocate any decor based on where the fan goes.

Odd thing is, the garden side of the tank which is always covered in condensation behind a large cork tree and moss pit (where it's impractical for me to wipe down the glass, and where a fan will be unable to reach) has no mold. We did find a piece of food that got dragged behind the tree and molded while we were gone, but that's it!

Hubby said he opens up one side of the tank (lid) he made something to hold it open to help with the condensation, not sure if that would help your situation out. I can take a picture of how it looks if you want.

Yeah I would definitely clean and bake dry all the affected areas. I'm not sure why MSW creates mold but it's a pain in the butt! I know some wood is more susceptible to mold than others I'm just not sure which wood is which. Lol

I've never gotten mold in my moss pits… knock on wood (moldy wood) lol - sorry for the humor. I know what you are dealing with is not funny. It sucks actually. I'm sorry you have mold. Good luck with the huge clean.


Sent from my iPhone using Tapatalk

MSW does not create mold. Mold is always going to be present in the tank in one form or another, it comes with crabbing.
Soaking in full strength salt water and allowing to air dry will help prevent mold, but it won't stop it 100%.

As mentioned above, the valves will help control the strength of the bubblers.

soilentgringa wrote:MSW does not create mold.

Right. I thought it helped *prevent* mold, which is why I was confused. Of course the other side is all cork so that may be why there are no issues! Guess I'll have to get used to this part of crabbing. Thanks.

The problem was more widespread than I thought. Right now no less than 7 wood items have been scrubbed with marine salt paste and are drying in the oven. Even the bamboo ladder I put in just 1 week ago had green mold on every rung. Hubby is researching what temps over what amounts of time will kill mold. Hopefully we'll be able to go longer than four weeks before we have to do it again!

I'm a little concerned the concentrated dried salt could burn the crabs, but I previously treated a piece of cholla this way and the crabs in the 20g used it all the time.

Okay, on to strategically placing the fan.


Sent from my iPhone using Tapatalk

MsWorld wrote:Hubby said he opens up one side of the tank (lid) he made something to hold it open to help with the condensation, not sure if that would help your situation out. I can take a picture of how it looks if you want.

That would be great! We had the lids off a long time today for the clean so for the first time almost all the condensation was gone. Then it took forever for the humidity to come back up... or not. I started questioning my gauges after two hours, popped in my old reliable and turns out BOTH my mini-gauges were reading 10% low! Calibrating now. Funny how every "quick thing" turns into a huge project!

When I said I had previously treated cholla by the salt paste method, I should have specified that I air dried it. For future reference, the oven bake method was really, really NOT the way to go. Unless I first bake just to kill the mold and dry the wood out, THEN salt paste and air dry. Baking the salt paste crystalized it instead of drying clear, and we spent another half hour scrubbing it back off all the wood! Even after that, my hands feel sticky after handling it (kind of like my hair does after a day at the beach). The bamboo tube is the worst, it appears to be "sweating"; the hubs wonders if the salt is drawing out all the moisture! Well, if it's obvious the crabs aren't using the climbing structures because of the salt, I'll pull them back out and start over. Live and learn!

We did get the fan in and I LOVE It. I'm ordering a second one and will either point it towards the other side of the tank, or have it as a back-up.

Mold spores are everywhere, in all homes, in all air we breathe. It just takes the right conditions to spawn and start growing. So far I have not had any mold issues in my tank bit it's still new so fingers crossed.....

We live in Florida, where the indoor humidity with the air conditioning on is 66%... I'm surprised we don't have more mold and mildew issues than we do!


Sent from my iPad using Tapatalk

I had issues with mold in my tank a couple of months ago. I took out all wood structures, soaked in MSW for several hours then baked in oven 275 deg for 1 1/2 hrs, then layed out to cool. My bubblers also are on a splitter with air flow control valves which help with splattering of the water. Couple of times a week, I wipe down the glass with white distilled
Vinegar to help with possible mold. I also installed a 5
Inch fan blowing across the tank - helps with air flow, decrease mold, decrease condensation on the glass, and, apparently a fun structure to climb after watching the hermies slide down it like spiderman! Good luck!

Thanks, @Kermie16! What you laid out is pretty much my plan after reading everyone's comments. I didn't know about the vinegar helping, though, I can try that. I just got a 3" fan that I adore, I'm experimenting with what direction it points and possibly installing a second one to make sure all areas of the tank get some airflow. How often and for how long do you run your fan?

hprmom wrote:Thanks, @Kermie16! What you laid out is pretty much my plan after reading everyone's comments. I didn't know about the vinegar helping, though, I can try that. I just got a 3" fan that I adore, I'm experimenting with what direction it points and possibly installing a second one to make sure all areas of the tank get some airflow. How often and for how long do you run your fan?

I had to experiment a bit with the bubblers running and off. What I found that worked for us was for it to run for about 30 mins about every 3 -3.5 hrs - a little less frequently at night because the temp and humidity would drop a bit. You will need to play around with it and see what works best for your little guys.