Lessons Learned During A Deep Clean 6

This is where you discuss the conditions of your crabitat -- temperature, humidity, substrate, decorating, etc.
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Lessons Learned During A Deep Clean 6

Post by JediMasterThrash » Fri Oct 06, 2006 10:48 pm

Please see my other post for pics and description of my new crabarium iteration. This post details lessons learned from my previous iteration.

First lesson, the most important, is about water quality. I’ve struggled with this a bit from the start. My first iteration, I had somewhat smaller pools, and I would fully clean them every week. That was my most successful crabarium, with only two deaths over 8 months. And this was despite the enormous amount of mold that grew on the wicker baskets that were half-buried under the moist sand. The next iteration I got the waterfall, which was impossible to clean. And then got a large pool with a table fountain in it, plus the waterfall. I thought that the constant circulation from the waterfalls would keep the water healthy, but I was quite wrong. I had a lot of deaths, especially the new delicate strawberries. So I got the 3-stage filters. The filters definitely kept the water cleaner. Even when dirty, it still smelled nice (as opposed to without the filters were dirty water smelt like rotten sewer). But the filters still aren’t enough. After about 3-4 months, crabs would start dying. It had to be the water. I think that you simply cannot cycle only 1/2 gallon of water. I think I read before during research that you need at least 5 gallons in order to maintain a cycled water system. So the upshot is, even with filters and clean water, you need to regularly completely clean the large pools. Especially since, even with the filters, the crabs simply poo faster than it can be filters. It’s amazing how much poo they can fling into the pools. And if you have coco-fiber substrate, whoo-wee!

In my last iteration, I didn’t have deaths for the first 4 months, and then suddenly started getting a couple a week. Then I started fully-cleaning out both pools (FYI, I always cleaned the filters once a week and replaced the carbon once a month) once a month, and after I started that, no more deaths.

The problem was that it was hard to clean out the pools. They’re in the back of the large tank, and half-buried in sand, and large and filled with water. Usually I wait until the water is low, empty what I can, them pull it all out, trying to be careful not to cave-in the sand-walls around the pools, and worried about disturbing crabs buried under the pools, and also having to re-level the pools, and hoping I don’t crush crabs when I put the pools back (the crabs digging would cause the pools to start leaning on the side or corner).

So, this time, as I explain in my other post, I put mugs under the pools to act as pillars. So now there’s a safe surface to place the pools on, without worrying about the crabs underneath. The pools are also up much higher now, since, as explained in my other post, I added mesh sides for climbing in and out. So there’s much less sand-wall on the sides. There’s a good 4+inches of depth under the pools now.

Second lesson, is about providing enough shelter on the surface. I went into detail in my other post, but my tanks had been getting rather sparse on the surface, and I’d been seeing much less of my crabs. They’d stay buried, or hiding in the bonsai. Usually just a few regulars who always enjoyed climbing on the waterfall and waited every night to be first in line for food would always be out. I figured that the problem is not enough shelter on the surface. They had to hide underground or behind the few shelters they had, and didn’t feel secure enough to be out and around the tank more often. So this time I added much more shelters on the surface. I put the two Chinese temples on the surface, plus a fake hollow-log, plus a real half-log, plus a hollow cork log, plus the bonsai, all on the surface. I’ve decided that jumbos and larger crabs are fully capable of climbing under or over things, so I shouldn’t worry as much about making sure there’s enough girth for them everywhere. And crabs prefer to bury by digging under something anyway, so I don’t need open sand for that. I also added real moss beds for them to bury into, and I doubled the amount of fake-plants in the crabitat so they have more security even when they’re out climbing around. I also put a wicker thing on the second level that has many hiding places in it.

The moss is also for the thought that strawberries or other crabs that have trouble molting might have an easier time being able to bury into a softer surface substrate than deep down into the sand.

Third lesson: I think crabitats need more daily variation in temp and humidity. In their natural habitat, the temperature will range 30 degrees from day to night, and relative humidity 25%. I think it’s completely unnatural to give them 24/7 of 78o and 75%. So this time, I placed both one of my night-glo fixtures (2x25w) along with the 15w repti-glo 5.0 fixture on the same day/night timer. So they’ll get 115w during the day and only 50w at night. The difference in radiation will chance humidity as well as it changes how fast it evaporates water from the pools, and of course relative humidity changes as a function of temperature too.

Forth lesson: No mold! There wasn't any mold anywhere at all in the tank, and I had cholla in direct contact with moist substrate for 7 months. It has to be some combination of the heat/lights, and the fresh airflow from the tropicair humidifiers. I think having higher temperatures and lights is really a main factor in keeping the mold from growing.

Stuck-up, half-witted, scruffy-looking crab-herder since '92.