Lessons Learned During A Deep Clean 7

[JediMasterThrash]

Please check out my "92g Mythical Valley Crabarium" post to see what I've done for my latest iteration. This post will describe what I've learned from my previous crabitat iteration.My last iteration consisted of three stages. First, was the regular 6-month iteration (which actually lasted 7 months). Second was the partial substrate change, which lasted 4 months. And third was my temporary move crabitat, which lasted 1 month.We were anticipating a move, which is why I did a partial substrate change instead of a full deep clean. I didn't want to dig up the crabs again a couple of months later.http://landhermitcrabs.com/eve/forums/a ... 1044222And of course my crabs needed a "transportable" crabitat for the move, so they were downgraded to the 55g.http://landhermitcrabs.com/eve/forums/a ... 81028942My previous iteration had sand on the inside/back corner of the tank, and eco-earth on the outside ring of the tank. I had fresh and salt ponds that were filtered. And I was doing the day/night cycle, where temp and humidity would increase and decrease throught the day along with timed lights.I did not feel that the iteration was a success. Something wasn't going well, and it wasn't obvious what. I was encountering regular deaths (like 1 or 2 a month). And during some previous iterations, I'd been able to go a whole year with only a couple of main-tank deaths.So about 4 months through that iteration, sometime around the start spring or late winter, I made a few modifications. During a prior iteration where I did not have good success, I determined that it was water quality that was the issue, so I took that road again. Instead of just cleaning my pond filters every week and changing the carbon every month, I also started doing a full clean of the ponds every month. Now that I have the ponds up on cups, I don't have to worry about crushing buried crabs under the ponds or anything, so it's easy to get the pond basins in and out (well, relatively anyway, it's a long reach into the back corner of the 3foot radius tank). First I'd save one cup of water from each one (preferrably get the cup before I stir up all the muck and make it dirtier), and then fully wash the basins, waterfall, and all the rocks. Then put it back together, and re-seed the water with the saved cup from each of them. 1-gallon ponds are too small to cycle, so this is kind of like changing 9/10ths of the water. And then in the meantime, the 3-stage filters should keep it fairly clean.I also had at one point put the 2nd set of night-glos back on full-time duty, rather than on the day/night timer, because the house temp during winter was just too cold to let only one set of night glos be on during the night. There was still a temp variation from day to night, because the house temp would stil lincrease during the day, and the reptisun would kick in. But not as much as before. But I actually think the day/night cycle is better, and reinstituted it later, I don't think that was a cause of the problems.I also occasionally take out the wicker baskets and clean them, because the crabs just really fill them with noodles fast. Helps keep the tank clean.I also used up my old Red Sea Salt at some point, and this time got some Instant Ocean to try out. I also at some point upped the dosage from 1/2 cup per gallon to 3/4 cup per gallon, and I think that has definitely helped with the more salt-water species.Of the crabs that died, it was completely across the board in terms of size and species, so I think that means that my conditions are equalized across the requirements of all the different species. During previous iterations, my deaths were usually weighted, like really high on straws (suspect due to too weak of saltwater concentration, and also insufficient above-ground hiding places), or ruggies.I also made another change to the water, but that will be a discussion in another post at some future date. For now, just lump it into "changes made to correct problem".I also had still been using up some old jurrassic diet food that I'd had once and didn't feel like wasting by throwing away. I was just feeding a little bit now and then, but that finally ran out, and I'm definitely glad about that (has copper sulfate, and the crabs are completely uninterested in it anyway).And then I did the partial substrate change. I added in coconut husk (little cubes) to add diversity to the substrate. "Grain" diversity. Theoretically, the larger chunks should help to aerate the substrate as they get moved around when crabs are burying. They also hold moisture well. And I emptied off my bag of flukers moss. But I'm kinda unsure about that. The moss just has such an odd smell too it, so artificial. It's definitely from the coloring, but we don't know what the "natural dyes" are, I just hope it's spinach-based. It never really stays in nice fluffy moss beds anyway. Within a few weeks, it's just trampled and tracked around the tank.So, what's happened in the half a year since then? Well, I'm happy to say I have not had another (known or above-surface) death since I started instituting all these changes, which has been probably about 8 months. Now that's what I like to see, back to the good old days, when you get into a nice streak like that. I just gets depressing when you keep seeing another dead crab every other week.And it gets better. I got 3 more jumbo straws. I'd had such poor success before, but I wanted to see if the stronger saltwater, cleaner water, or denser jungle crabitat would help. Well, a milestone was set, as all three are still alive, and one of them actually molted!One of my favorite guages of crab happiness is surface daytime activity. And my crabs have definitely been showing good surface daytime activity. And the denser crabarium I think definitely helped. In the prior to the previous iteration, when my surface was sparse, I'd rarely see a crab walking around. But now that here's plenty of caves and tons of foilage, the crabs seem to be visible (even if they think they're hiding) more often. And they still like to bask under the lights.Another thing to note is the cycles the crabs go through. What I call "molting season" for absolutely no scientific reason, but probably it's more likely mating season. In the late fall and winter, the crabs tend to not be as active, and simply don't eat. Sometimes the food will sit for days being untouched until I have to throw it. And then in the springtime, suddenly their appetites perk up, and they will devour a whole bowl of food within an hour multiple times a day. Their appetites are just insatiable. Through the summer their appetites go back to a normal level, which still requires feeding every other day. Late summer/early fall they go through another hunger spike, and they do a lot of digging then too.During the deep clean (when I moved the crabs into their temporary crabitat for moving), I discovered the usual ratios of crabs. About 1/3rd were visiable on the surface, 1/3rd were on the surface but hidden, or buried directly under a toy, and 1/3rd were buried in the substrate. The vast majority of the buried ones were all the way down to the bottom glass too, as usual. It's relatively rare that I did up a molter requiring ISO. Once every other deep clean at most. This time, I dug up one crab who had recently molted, but was mostly hardened and eating most of the exo. I ended up letting him back in with the crew, and he's finished up fine with no problems. And also, nobody ever attacked him (molt smell is a myth, in my opinion).Ok, here's where it gets back to bad. First, over the course of the previous 8 months of no known deaths, I'd still occasionally just find

an empty shell on the surface. It didn't seem that it fell from the shell basket, so I figured it must be from a dead crab. But I'd search and search and could never find a dead crab. One of three things. Either a crab molted and lost it's shell (impacted shell while buried, had to abandon it), shell did fall from the basket, or shell from a buried but dead crab. Eventaully, due to all the digging, buried things will find their way back up to the surface. There's also a 4th possibility, which was when I had that naked crab with the molt deformity, he would constantly try out a shell for a while, and then abandon it on the surface and go naked again.Well, after my head count, I came up 18 crabs short... Now I've come up 1 or 2 crabs short before, and I can understand they probably died underground long enough ago to have gotten reabsorbed. And there's always a margin for error, where I forgot to check off a known surface death. So maybe a few could be from that. But at least 15 crabs had to be completely missing. They didn't escape - the cats would have found them, and we would have found them when we moved.So it must be that the crabs died while buried, their bodies biodegraded, and eventually the shells filtered back up to the surface (there were also a few shells I found under the surface, but no sign of crab at all).So now we have to establish time of death. I hadn't noticed any missing crabs since the changes, but I had noticed missing crabs (crabs that buried but never resurfaced) during those bad first 4 months. During previous deep cleans with eco-earth, I'd uncovered crabs in various stages of biodegration, so I could determine +/- a month how long it takes to reach certain stages, and I can say that it definitely takes 4-6 months to reach the "completely disappeared" state, with nothing left to identify that a crab was ever there. So dating from the few shells I found under, and going back through 6 months of dug-up shells, I have to conclude that nearly all of the "missing" crabs died or buried during that initial bad 4 month period, before I instituted he changes. As I said, I didn't find any sign of a dead crab when I did the deep clean last month.So, now, this just disturbs me. I mean not just dying crabs, but the fact that eco-earth causes them to biodegrade fast enough to completely disappear within half a year. I liked it better back when I had all-sand, and the buried dead crabs would remain as something you could recognize as a crab for much longer (usually they would start to mold in the sand, and you could find a wad of mold at the entrance of a buried shell to determine a crab had died there). This is part of my reason why I did not add any new eco-earth to the tank for my new iteration. I just got 4 bags of playsand and that was it. My most successful iterations were all playsand iterations. Sure the crabs enjoy burying, and even molting in eco-earth, but somehow, it seems I have more success with playsand, so at least for this iteration, I'm going back to that.I saved a bag of top-soil substrate from the previous iteration to reseed the new iteraiton with. So there is still some eco-earth, coconut-husk, and moss along with that. But the ratio is around 1:10 instead of 1:2.One last piece of bad news (also reported in my moving post). My moonglo fixture had been running the same original moonglo bulbs since November 2003 - 32760 hours of straight running time. That has to be some world record. But turning them off and on manually a couple of times on the temporary moving tank caused them both to blow out one time when I turned them on. So now the calander is ticking on my new bulbs FYI, I don't think it's necessary the bulbs (though they are the exo-terra brand), I think it's the fixture itself. This fixture I paid 60$ from oceanic systems from when I got my corner tank. High quality. The other fixture that blew out moongloes every 3-6 months, and eventually blew itself up, I'd found at a thrift store, and was probably older, and didn't have any wattage ratings written on it.Ok, forgot to add this one. More bad news. If you recall my post about my naked crab with a mold deformity, well while counting the crabs during the deep clean, I noticed about 4 other E's with assorted molt deformities. Nothing really bad, mostly just oddly bend legs, that kind of thing (the naked crab had a warped carapace and couldn't fit into a shell right anymore). Now first, it was all Es that are having this problem. And too many to be conicidence. Now they are older, more established, so it could be something that's built up over a long time, like, say, food preservatives. I point my finger at that darned Fruit and Flower treat. I'd still been giving a little bit, just because the crabs like it so. But that's the only thing left I've been feeding that has questionable ingredients (copper sulfate). So, I'm going to have to ditch it now. No more copper sulfate in my food anymore. Not after seeing these E's start to develop molting deformities.http://landhermitcrabs.com/eve/forums/a ... 8751061522

[JediMasterThrash]

search "copper sulfate" and "ethoxyquin" and "deformities" on the LHC and HCA forums for answers to that question. It's too long an issue to make a quick response too.Actually, you'll probably have to search the LHC archives manually, I still can't get the searches to return results in the archives.The basics are that certain ingredients are common use in dog and cat food, and were brought over as preservaties and mineral compounds for hermit crab foods as well. However, even though they are safe for mammalia, they are toxic to arthropods (of which hermit crabs are members). Some are even insecticides (which again affects hermit crabs).Obviously no one would purposefully feed their crabs insecticides. The issue at hand is the amount present. Many minerals are necessary to survive in the right concentrations, but become deadly in overdoses. Many toxic compounds are harmless in low enough doses, and sometimes even beneficial. The amounts of these compounds are usually measured in the parts per million, which amounts to micrograms per serving. Nobody really knows what the threshold is for crabs, though thresholds have been set for human and dog/cat consumption.I can't say why it just affects the Es. Perhaps other species died, rather than surviving with a deformity. E's are rather hardy.

[Nicole]

Thank you for all the updates! As an all playsand user, I have a question: What made you decide that you had more success with playsand? I always waver back and forth about adding EE to my sand or going to all EE, but my only reason to switch is because of the packing and drying of the sand during molts. Do you not have much of a problem with the sand doing this?

[JediMasterThrash]

I don't use UTHs in my main tank, so I haven't had any problems with packing or drying. Usually just the surface dries from the lights, but I add a cup of water to the substrate every now and then.I determine "true" success by how many deaths I have and how many successful molts I have (well, I guess if it's not successful, it's a death).Take how many crabs you have (C), how many die in 6 months (D), and calculate your crabs average lifespan as the half-life of your population.Deaths per crab per month = D/(6*C) = d. Assuming constant death quantity (a constant rate below 1/3rd would converge to no deaths, but in reality, the probability of death increases with the time the crab spends in captivity, so we'll simplify it to a constant death quanitity), then you'll lose half your crabs when C/2 = C*d*M. So M = 1/(2*d).The number of months it will take for your crab population to half is then:M = 3*C/DWhere C is the number of crabs you have, and D is the number of deaths in 6 months.So if you have 30 crabs, and you lose 3 in 6 months, then your average crab lifespan is:3*30/3 = 30months = 2.5 years.Long ago, half-lifes were on the order of 6 months. Now, 2-5 years is common for experienced crabbers.I also take into account the length of time the crab has been with me. If the crab has not yet reached its first molt in captivity, then it's chances of dying are higher do to irrevocable problems prior to ownership. Once a crab has survived a molt, then it becomes a main-tank crab who should live for at least 5 more years (preferrably 30 years).So if I start losing established crabs, then something is definitely wrong. If I lose 3 or fewer crabs, all or most of which are pre-first-molt crabs, then I consider it a success.My crab population is usually in the 30-50 range, depending on new purchases and adoptees.