PPDS Prevention Method- Helpful or Harmful?

[crabbyvee]

Hi all. I just recently got my hermit crabs and have been doing extensive research to make sure they have a proper setup and don’t die. From my research, I found multiple reliable sources (Crab Street Journal, Crab Central Station, etc) that promote the PPS method of gradually raising tank temp & humidity over a 3-4 week period to acclimate the hermit crabs but most importantly, to make sure they eat properly and are nutritionally prepared to molt.
However, I’ve read multiple threads on this site that say it doesn’t actually help, does more harm than good, etc. I’m feeling torn as to what will actually be best for my crabs. One of them has buried beneath what little substrate is in the tank (only 1-2 in. per PPS method) and I’m worried he’s going to attempt to surface molt. I’m prepared to just cover him w a 2 liter bottle but tbh, if this method isn’t best, I’d rather know now so I can properly prepare my 20 gallon and get them in there ASAP before the little guy decides to molt. Thoughts???

[hermitsinnc]

My adapted version of PPS was to start with the shallow substrate/no places to hide so they would focus on getting good nutrition before molting, BUT I kept the temp/humidity within the recommended range. And when I noticed the pre-molt symptoms, I moved them out of it ahead of schedule so they could do a proper underground molt.

I would personally recommend upgrading them to deep (6+ in) and sandcastle consistency substrate ASAP so you don't have a surface molter.

[CrabbyLover77]

I've adopted quite a few crabs, and I always follow HCA's advice about not using that method. I get the crabs into good conditions, including sufficient substrate, right away. I still have many of these crabs 2-3 years later since I started rescuing in 2019.

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[wodesorel]

You cannot stop a crab from molting if it needs to molt, so forcing them to do so on the surface because they can't dig is where it becomes dangerous. Please understand that their method was based off of reptile rehabilitation of severely abused and starved animals, not arthropods (crabs) and not with wild caught individuals. Crabs have been supplied nutrition along their journey and are not malnourished when they arrive. I know people freak over pellet food, but it is still food and it provides them with they need. It's also well understood with invertebrates, and even with marine animals in general, that they need to get back into proper conditions as fast as possible, as prolonged improper conditions cause more physical damage. Even the reptile method that was used is a gradual environmental adjustment of hours, not weeks. Vertebrate animals with complex digestive systems do take a slow adjustment and rehab period when it comes to introducing food back if they've gone without for an extended period, or else their digestive system becomes overloaded. This is not a concern with invertebrates.

[crabbyvee]

My adapted version of PPS was to start with the shallow substrate/no places to hide so they would focus on getting good nutrition before molting, BUT I kept the temp/humidity within the recommended range. And when I noticed the pre-molt symptoms, I moved them out of it ahead of schedule so they could do a proper underground molt.

I would personally recommend upgrading them to deep (6+ in) and sandcastle consistency substrate ASAP so you don't have a surface molter.

So this brings me to my next question- I’m waiting for some supplies to come in the mail before I can switch the crabs over into their big tank. How long do I have before the suspected molter begins to release the smell that makes the other crabs want to eat him?

[crabbyvee]

My adapted version of PPS was to start with the shallow substrate/no places to hide so they would focus on getting good nutrition before molting, BUT I kept the temp/humidity within the recommended range. And when I noticed the pre-molt symptoms, I moved them out of it ahead of schedule so they could do a proper underground molt.

I would personally recommend upgrading them to deep (6+ in) and sandcastle consistency substrate ASAP so you don't have a surface molter.

So this brings me to my next question- I’m waiting for some supplies to come in the mail before I can switch the crabs over into their big tank. How long do I have before the suspected molter begins to release the smell that makes the other crabs want to eat him? Like how do I know for sure that he’s molting and when to start protecting him?

[hermitsinnc]

So this brings me to my next question- I’m waiting for some supplies to come in the mail before I can switch the crabs over into their big tank. How long do I have before the suspected molter begins to release the smell that makes the other crabs want to eat him? Like how do I know for sure that he’s molting and when to start protecting him?

I'm not exactly sure about the smell. If you see him with exo hanging off (it may look like a dead crab), then he has molted and should be in ISO for sure while his new exo hardens.

As long as you have the sand/whatever you're using for sub now, I would go ahead and move them now. Whatever water/food/dishes you have in their PPS setup will work fine, and they can do without hides and climbing structures for a few days. You can use plastic wrap for a lid, and alternate heating methods should work for a few days if you're waiting for a heater (if the heater you're currently using is Ultratherm, you can transfer it over). The most important thing at this point is deep sub so he can molt properly.

The 2-liter bottle method works well IF you have a surface molter, but it's not ideal. The best-case scenario is for him to molt underground and come up when he's ready.