PH level of substrate in areas where Hermit Crabs reside

[samurai_crab]

Easy test, take leftover exo from crabs molting and put it in vinegar, or something equivalent to the pH of cocofiber. What is the pH of cocofiber? Now this isn't an exact comparison to what it would do to a living crab, really no way of experimenting on that without being extremely cruel to the crab and this doesn't account for what an acidic substrate would do to a freshly molted crab (again only way to find this out would be cruel).

[kgbenson]

Also, I don't think the shell argument is valid.

I think I said that.

Shells are composed primarily of aragonite (calcium carbonate). Hermit crab exo is mainly chitin (closely related to glucose, a sugar). Comparing the two is like comparing apples and oranges.

I think I said that too.

Just because a shell dissolves doesn't mean that a hermit crab will.

I think I alluded to that when I said I did not know about the bad molts and pitted exoskeletons.

How about this one - in my freshwater tanks, seashells dissolve quickly, yet I had ghost shrimp stay alive for over almost two years without melting.

Yep. I don't think I ever said anything that would contradict this.

Going by the theory that since the shell dissolves so should the crustacean, then the shrimp should have been dead a whole lot sooner.

Are you suggesting I had theorized this? If you are you might want to re-read what I wrote.

I am not suggesting that the pH is necessarily a problem, merely suggesting that no one has posted data suggesting one way or the other, the information you garnered from your parents profession notwithstanding.

I don't have a dog in that fight, i just don't like it when people use info to infer far too much.

I have suggested that pure coir takes the shine off of shells faster than sand.

Keith

[sugarselections]

Easy test, take leftover exo from crabs molting and put it in vinegar, or something equivalent to the pH of cocofiber. What is the pH of cocofiber? Now this isn't an exact comparison to what it would do to a living crab, really no way of experimenting on that without being extremely cruel to the crab and this doesn't account for what an acidic substrate would do to a freshly molted crab (again only way to find this out would be cruel).

On the previous page Wodesorel stated that the pH of coco fiber can range from 5.5 to 6.8. So I guess depending on what type of coco fiber you buy your substrate may actually be pretty close to neutral. The pH of vinegar is much more acidic at about 2.4. Not really very comparable.

Anybody know how I would go about testing the pH of my substrate? I think I have some aquarium test strips left over. Could I somehow use those to test soil?

[JediMasterThrash]

I think these two statements are largely at odd with one another.

Keith

You may be inferring more than I intended.

I'm talking about surface molts in the more general sense of just "not buried under the substrate (sand/coir)".

As was intended in my post, I was talking about molting under decaying forest litter, under piles of moss, leaves, etc, as opposed to burying under sand to molt, and I was referring to molting under leaves and moss as a "surface molt" for the purpose of distinguishing it from a subterranean molt.

To read between the lines, my intent was to bring up discussion of whether, in the wild, the substrate acidity is that important to molting, if in some circumstances they may molt "above ground" so to speak?

And I was curious to see if any members have experience with "Surface molts" in moss pits, under surface litter, etc.

[wodesorel]

Just FYI, I'm a bit high on Vicodin for a back injury right now. (Just cleaned the 135 gallon top to bottom - bad idea!) I think I'm making sense, but that might just be me.

I was much more clearheaded earlier in the day before the drugs, but obviously I still screwed up what I meant to say. I'm not trying to pick a fight Keith. I'm merely addressing points I've seen again and again on this forum.

You did say that shells and exo aren't the same thing, but I think clarifying what they are composed of helps everyone understand. The fact that shells will dull in cocofiber has been used by some people on this forum to show that coir must be dangerous to the crabs - however with different compositions that cannot be inferred by such a simple shell test. I never said it was your theory, but it is an active argument that is still being used and I felt that it needed to be addressed. Perhaps I'm just beating a dead horse by stating it, but I feel it's important.


samurai_crab, old crab exo could be placed into coir and left there moist for an extended period of time rather than trying to use something else. If you wanted to use another liquid that is common then the pH of milk is between 6.5 and 6.8, which is the upper end of what coir tends to test at. Black coffee is actually more acidic than coir with a pH of around 5. Handsoap should fall between the two.

I'm not sure that aquarium test strips can be used for testing soil pH. I mean, it can be done, but I can't find any info stating the testing would be accurate. In order to perform the test you would mix 1:1 soil to distilled water. (Must be distilled as it should have a pH of 7.) However, it is the planting time of year and soil tests are easily available if anyone is feeling sciency. University Extension offices also do soil sample testing for everything including pH for under $10, if someone was really interesting in figuring it out.

Edit: Yes JMT, I have had a few moss-pit molts - at least seven that I know of, but Firefly and Kratosa were so small and molting so often that they could have easily had pulled a fast molt without me seeing it. The molts were extremely quick - lasting only 3 to 5 days start to finish. The biggest crab I had that molted in the moss pit was a medium, and all of the crabs have had a few regular molts since.

[samurai_crab]

Although I iso'd my most recent moss pit molter, it was still a very quick molt. She ate her exo in all of about 2 days I believe, no more than 3 and was ready to go back into the tank in 4-5 days max.

[suebee]

The shells being damaged is a concern due to the shells being the protection of the crabs. A shell that is being damaged could result in a broken turbo inside the shell. It also results in ugly looking shells. My concern it what the Coir is doint to the Exo of the crabs. I adopted crabs that had been living in EE for 4 years.. All of them had legs that were not straight.. I know for sure others here that claim to have not had any molting issues and use total ee as substrate HAVE said that they did have crabs that have come up with legs that were not straight and looked to be a bit handi caped. The crabs that i adopted had pitty Exos that unless you saw them against the smooth healthy crabs i have you may not of noticed this. With in A year in the substrate of 5 parts sand and 1 part EE all of the crabs had molted at least once and all of the limbs are straight and healthy. No more pits.. all of them have ditched the ugly stained and pitted shells and they look like different shells. The person who gave them to me did not even recognize them as her crabs that she had for so long. Whe she saw how much they changed she cried. She was one who i often suggested to change the substrate but didnt want to fix what she didnt think was broken. When she saw the difference she felt she had been doing her crabs an injustice. She also was a person who buys my food from my hermit crab dollar store so i cant say it was a feeding difference. This was a final straw for me to see it in person. Not to mention the 100s of thousands of crabs that the hermit crab patch and ELHC has seen do better with the 5:1 substrate..

[kgbenson]

On the previous page Wodesorel stated that the pH of coco fiber can range from 5.5 to 6.8. So I guess depending on what type of coco fiber you buy your substrate may actually be pretty close to neutral. The pH of vinegar is much more acidic at about 2.4. Not really very comparable.

Sigh. for the purposes of illustration here they are dead on comparable. The issue is what does acid do to a gastropod shell. At the pH readings mentioned above calcium carbonate is going to dissolve. It will do so more rapidly in the vinegar and with visible bubble production - thus making a more striking display of the general principle of the increased solubility of calcium carbonate with lower pH. Or you can do what I did - bury some shells and check on them over a few weeks to months. The shells in the coir etched faster than in sand (silica sand) This effect would be more pronounced if the sand was moistened with fresh water than with marine salt water because the pH would almost always be lower.

At a pH of 7 you can dissolve about 16 grams of calcium carbonate in a liter of water. Increase that a bit and it drops precipitously, at a pH of 8 it is a thousand fold less soluble. That is two orders of magnitude.

Here is the important point: calcium carbonate is going to dissolve whether the pH is 2.4 or 6.8, the only thing different is the rate of dissolution. Spot on for demonstration purposes, apples to apples, easy to replicate at home and easily understood.

Anybody know how I would go about testing the pH of my substrate? I think I have some aquarium test strips left over. Could I somehow use those to test soil?

Not really. Send a sample of to the local extension service for a soil pH level, usually this is about 6 bucks.

Keith

[kgbenson]

You may be inferring more than I intended.

very possible, these internet discussions can sometimes be challenging

I was referring to molting under leaves and moss as a "surface molt" for the purpose of distinguishing it from a subterranean molt.

gotcha - I can see soem of the confusion.

To read between the lines, my intent was to bring up discussion of whether, in the wild, the substrate acidity is that important to molting, if in some circumstances they may molt "above ground" so to speak?

Excellent point.

And I was curious to see if any members have experience with "Surface molts" in moss pits, under surface litter, etc.

Gotcha. I had one. in a moss pit, several under cage furniture, many deep in the substrate (8-10 inches on the glass bottom of the enclosure) if that helps.

My impression of the moss pit molt was that the animal was abnormal based on some of it's pre-molt behaviors. But an N=1 is not enough for me to speculate. My understanding is that Indos, particularly the larger one's not infrequently molt under a structure like a dish, flat rock etc.

Keith