A Discussion on Substrate

[MacandHunter]

I wanted to have a discussion about substrate. I don't know if I've missed the memo, but recently there have been recommendations by a couple of people to use the 5 parts sand, 1 part EE mix. (with the crushed oyster shells)

I wanted to hear why this is a good idea, and have a general conversation about what type of substrate we all use, and how it's working out. First, if someone can explain, in their opinion, the benefits of the above mix that would be great.

[SebbyCrab]

I use a mix. I've found a mix makes it a bit easier to dig, maintain humidity, and keep the substrate the proper moisture. The crushed oyster shell idea makes sense because the crabs eat the substrate, them picking up the oyster shell from the substrate would be a good thing.

[MudCrabDude]

I remember having a discussion on this a long time ago I think when Tojo first signed on. This is what I've dug up from the internet, and I have bookmarked ever since:

http://talkto.thefrog.org/index.php?act ... opic=16430

Safe And Effective Substrate Mixtures For The Vivarium

Terrariums & Vivariums
The terms terrarium and vivarium are often used interchangeably, or to differentiate between a terrestrial habitat and a semi-aquatic one. Technically, there is a more fundamental difference separating the two. The term terrarium should be applied to an enclosure meant only for the life and the propagation of plants, such that the substrate, lighting, and other environmental conditions are tailored to meet the requirements of specific species. A vivarium, on the other hand, is an enclosure meant to house animals or invertebrates, with environmental conditions suitable for the life and propagation of the particular species. Specifically, vivariums are enclosures for reptiles, amphibians, and other smaller animals and invertebrates that require an earthen or aqueous environment. There are many types of vivariums, such as aquatic enclosures (aquariums) and bog types (paludariums), collectively referred to as vivaria. There are further divisions to each type of vivarium, such as arboreal, fossorial, desert, wetland, shoreline, cloud forest, etc., that are designed to meet the needs of the particular inhabitant.

For completeness, there are other types of captive environments that do not fall under the vivarium category, such as aviaries and cages.

Both terrariums and vivariums require a proper substrate with significant biological activity, however, the requirements of the vivarium substrate are a bit more complex. The vivarium substrate must be able to break down organic matter, such as feces, shed skin, and uneaten food. It must be able to maintain a variable degree of moisture, without clumping, turning to mud, or drying out, and cannot contain noxious or toxic materials, either man-made or natural. The media must also be able to withstand the physical activities of the inhabitants, without significant modification of its composition. It must remain aerated, moist, and nutrient rich, and must not only house, but maintain a healthy colony of beneficial bacteria. A good substrate can last for years in an enclosure, and is a necessary requirement for healthy inhabitants. All too often poor substrate results in unhealthy captives, death, or at the least, constant reconstruction of the enclosure.

Most all substrates smell earthen when first laid down, but after a while, a bad mixture will develop a sour, rotten smell, indicating the need for replacement. This is common in many vivaria, and is an indication of poor soil mixture. It may be too wet, with pockets of stagnant water where bacteria and fungi have built up, or it may lack nitrifying bacteria required to break down organic matter. Some substrates settle after a while, becoming hard and packed, and drying out easily. A good mixture will smell fresh and earthen for years.

A Note About Beneficial / Nitrifying Bacteria
Beneficial bacteria is one of the most important elements of the substrate, as it maintain the nitrogen cycle by breaking down organic matter into "plant food", and helps fight and prevent the spread of harmful pathogens that may be brought in on the inhabitants. Without a descent supply of nitrifying bacteria, organic matter will not break down, instead rotting at the surface and turning into toxic materials, and harmful pathogens may run rampant throughout the substrate. The latter often causes serious health problems with imported animals carrying potentially deadly pathogens. Such animals are usually stressed upon arrival, which can weaken the immune system, and putting them into a sterile enclosure, where harmful pathogens can spread uninhibited, is often a major cause of death.

Bacteria are introduced into the enclosure via materials collected outdoors, from healthy environments. In the forest vivarium, decomposing leaf litter serves to introduce a starting colony of bacteria. In the bog-type vivarium, this is accomplished by the addition of fine silt from an natural pond, or by adding of portion of substrate from an established aquarium.

Substrate Ingredients

* Leaf Litter
Decomposing leaf litter from a non-polluted forest is an essential element in any healthy vivarium substrate. Natural leaf litter not only adds texture and nutrients to the mixture, but also introduces beneficial bacteria and fungi. In addition, small invertebrates are inevitably picked up in the leaf litter, which add to the biological activity of the media, and can serve as potential food sources for the inhabitants (depending on the species).

In non-trafficked forests, fallen leaves pile up around the bases of the trees throughout the changing seasons. At the top of the leaf litter will be the most recent layer, which should consist of whole, newly fallen leaves, in an early stage of decomposition. The lower layers are more decomposed, with the very bottom layers turning dark brown or black, and taking on a crumbly, soil-like composition. Materials from the top layer, all the way to the bottom layer, where the leaf litter meets the ground, should be used in the natural vivarium. Simply put on a pair of gloves and fill up a bucket, as needed.

Stiffer types of leaves are preferred, such as scrub oak, alder, elm, birch, aspen, poplar, beech, apple, ash, holly, and privet (Searcey, 2001). Avoid using soft leaves, such as maple, mulberry, sweet gum, magnolia, and tulip tree, as these will turn to mush as they decay (Searcey, 2001). Also avoid noxious species, such as eucalyptus, oleander, melaleuca, pepper, bottlebrush, and brugmansia (angel's trumpet) (Searcey, 2001).

Make sure the spot of collection is not chemically polluted, otherwise serious health issues can arise in the captive environment. Many parks are sprayed with insecticides several times a year to kill off wasps, bees, ants, and other picnic invaders. For this reason, parks and other recreation spots should be avoided as much as possible.

* Coconut Husk/Bark
Coconut husk is often available in the form of cubes, irregular chunks, or fiber (coir). The larger, chunkier types play an important role in drainage, and aeration of the vivarium soil. These should be mixed into the soil medium in moderation, as too much coconut material can lower the pH of the soil too much. This may be desirable in some cases, but many species are susceptible to highly acidic substrate, so always check the requirements of your captives first. Coconut cubes chunks take an extraordinarily long time to break down, and so will remain intact for years in the vivarium.

* Compressed Ground Coconut Husk Fiber [or EE]
Coconut husk is often ground and sold in compressed blocks that expand into a fluffy material when soaked in water. Coconut fiber, also called coco-fiber or coir (EE) serves as a "filler" in the medium, and also aids in moisture retention. Coconut fiber should be used in place of peat moss because it lasts much longer, is less acidic, and does not inhibit the growth of bacteria (Searcey, 2001). Coconut fiber is also more environmentally friendly than peat moss because it is harvested from farms, whereas peat moss is taken from the wild.

* Ground Palm
Ground palm serves the same purpose as coconut fiber, that is, to create a light, moisture-retaining material, but also aids in drainage. Ground palm also provides a source of beneficial bacteria and fungi (Searcey, 2001).

* Orchid Bark & Xerimulch
Bark is added to the mixture to increase drainage and aridity. Orchid bark is used as a substrate to grow orchids on, and consists of cubed or irregular shaped pieces of bark from various tree species, but often firs (Searcey, 2001). Xerimulch, by Kellogg Co., is a similar landscaping mulch.

Fir bark can be purchased in other forms, and is a good choice for the vivarium because it does not contain toxins or noxious resins, phenols, or sap (Searcey, 2001). Avoid pine, because of its noxious sap, and redwood bark because it contains bacteria-inhabiting properties (Searcey, 2001). Also avoid eucalyptus for the same reasons.

* Inert (biologically inactive) Sand & Gravel
Inert sands and gravel are used in bog type vivariums (paludariums). This type of ingredient should be comprised hard, inert rocks, such as granite or hard sandstone (Searcey, 2001). For acidic and neutral environments, avoid materials that raise the pH, such as calcium-containing substances, limestone and other types with high amounts of lime, or soft marble (Searcey, 2001). Also avoid chalky or metallic types, and those with patches or veins of bright colors, such as red, blue, or yellow (Searcey, 2001).

While you can go more elaborate with land hermit crab vivarium setups, like SebbyCrab says, I think the 5 parts sand, one part coir (EE) helps in the ease of digging, plus with the added benefit of being able to possibly allow beneficial bacteria to grow like as in the sandy soil in the wild around the forest beach areas where wild hermits live. I remember seeing wild ruggies around where the forest meets the beach areas, and the surrounding soil was essentially being mixed together with sand - so I suppose one way of simulating this is to add a bit of EE into sand (short of actually adding real soil into your sand - ideally this is what I'd do, if it weren't for the fact that I'm not really too confident of the soil around where I live, so I guess it will be EE then...)

Adding EE also has the benefit of taking up more volume (for the crabs' burrowing needs) but not adding as much weight if it were just pure sand.

Currently, my substrate mixes with EE has had fewer (if any) of those noxious dark spots (bad, stinky bacteria, I suppose, for lack of a better term) when just using plain sand in the past and the hermit crabs buried any uneaten food. I guess the "beneficial" bacteria (when mixing sand with EE) does inhibit a bit of the "bad" bacteria from growing when the hermits bury food or poop....

[tnt4eva]

I started out with a 50/50 mixture of coconut fiber and beach sand. After a deep clean I decided to have one small section of 100% coconut fiber, one section of 50/50 and one section of 100% sand. Occassionally the crabs wander onto the coconut fiber, but they never burrow there. They don't seem to have a preference as to 100% sand or the 50/50 mix.

[suebee]

Sad to say one of the best threads talking in detail about substrate was deleted and not edited to be re-posted with all the great info. This one however does go over lots of information one substrate

http://www.hermitcrabassociation.com/ph ... ht=#697750

Its a subject talked about many times in threads..

[MacandHunter]

Thanks for the great replies, everyone. With all my tanks overtime, I've used a large range of substrates. From all EE, all sand, half and half, etc. Right now I've got one tank with about half EE and half sand, and the other one that I just did a deep clean on, I went to all sand. The crabs don't seem to care either way. I haven't had any problems with them not being able to dig down in either substrate, and humidity isn't a problem.

It seems like the 5:1 ratio is small. I read some of that article (it's a bit wordy) and see the benefits of EE, but if only 1/6th of your tank is EE, is that really enough to make any positive difference? How crucial is it to have a tank with that 5:1 ratio? I've been crabbing for almost 6 years, and can only point to one possible substrate related death, a bacteria infection. I'm not sure if that was even the cause though. Part of my point is this: when giving the basics to new crabbers, is it too silly to suggest they have a 5:1 sand to EE ratio in their first tank? Aren't their other more important areas, and basic ideas, that we need to have them focus on first?

I'm also big on getting the conditions as close to the wild as possible. Mud, you mentioned ruggies. Do you, or does anyone else know if other species live in sand/forest areas, or more one way or the other?

[suebee]

Mac I would say all sand is a great substrate. The small percent of EE helps those that need to get more humidity into the tank. I would say more EE is a problem but some here seem to have success with all EE?
Most new people have some issues with humidity and adding some of the EE to the sand is a big help. I like to put the oyster shell in so my molters have more then just EE to munch on. Its a great way to get more calcium into the crabs. Very benificial to the crabs. Also EE helps break down waste in the tank. Good V bad Bacteria. I would say yes its a great idea for a new person to start with a great substrate.

lots of crabs live miles from the beach and only return to the beach to lay eggs. Violas live in trees often. Aussies go many miles from the ocean.

Id say your choice of substrate is a good one and I wouldn't worry at all.

[MacandHunter]

Thanks. I'm not worried about my substrate choice - like I said I've had almost no problems with substrate for almost 6 of crabbing now. I was just curious about the 5:1 ratio.

I think it's good to suggest that ratio if someone is having trouble with keeping their humidity up. I don't think we should stress a specific ratio on newbies, though. At least I don't think it should be presented as the only choice of substrate. There is so much for a new crabber to learn, and not having a 5:1 ratio never killed anybody.

[suebee]

I did have deaths that were due to more EE then the 5:1 amount. So I always will stress that 5:1 is a safe substrate used by ELHC and The Hermit crab patch. They both have many many years of testing on different substrates and found that 5:1 seems to be the safest. Its what they suggest so I too will always suggest what I feel is best for everyone. I think just especially being new you would want to know what people with years under their belt use with success. I have had hermits for 15 years now and only had problem with unexplained molting deaths When i used a little bit less then half EE to sand. I lost some very important crabs to this and do not want to see others go through that. Again I will say that some here have had luck with more EE but I chose to go with the numbers of crabs that our importers have had over many years and the testing they have done. I can also add that I too found the same problems in my own tanks.

When i was new i didnt want to hear what will work, i wanted to know what veteran crabbers felt worked best.

[wodesorel]

I just find it interesting on how much opinion has changed on substrate in the last 15 years. I was doing some research last month and stumbled across a old usenet posting from the late '90s in which serious crabbers swore upside down and backwards that playsand was causing deaths in their crabs! (Because it was a brand-new idea, people were questioning it's safety.)

Does anyone know about the evolution of substrate to this point? That was the only article I could find on the subject, and now I'm really intrigued. I'm sure the internet had a huge part in shaping basic crab care into what we know today. I would love to know how thoughts have changed over the years!

[suebee]

Over the past 9 years soooo much has changed about hemit crabs.. I know that I try not to look at internet data because it can influence judgment and not everyone posts on the net. Even some of the postings of data and ligature within this site is very old. This is the reason I asked the people I know that have had crabs in very large amounts for many years. Some of the places actually wouldnt discuss what substrates they use. The hermit crab patch and Exotic Land Hemit crabs were not only happy I asked they let me know why they chose the 5:1 mix and how they have seen improvement in all the crabs. One place is in DE and one in FL but both seem to have come up with the same mix. I was lucky enough to see the Crabs and Im so impressed with the health of them.
I also promised to let as many people as possible know of the findings.
They also told me about the findings of when they tried using calci sand and total EE as substrate without success. Calci sand sticks together and traps crabs and they found that EE can biodegrade a molter. That was the findings of them with very large amounts of crabs over many years.
I know some here have had luck with other substrates and I hope it continues. I plan on going with the research and what i feel is safest for my crabs. I have only had one death in the time I have been using this substrate and it was due to a collapsed turbo (inside spiral of the shell broken out) cutting my guys body. It was a very hard loss because that crab had been with me for 14 years...

[Guest]

Thanks. I'm not worried about my substrate choice - like I said I've had almost no problems with substrate for almost 6 of crabbing now. I was just curious about the 5:1 ratio.

I think it's good to suggest that ratio if someone is having trouble with keeping their humidity up. I don't think we should stress a specific ratio on newbies, though. At least I don't think it should be presented as the only choice of substrate. There is so much for a new crabber to learn, and not having a 5:1 ratio never killed anybody.

As a newbie I want to have all of the information I can get up front. As a fish keeper I try to set up my tanks as close to natural as possible and I would want to do the same for any small animal, like hermit crabs. I don't see why it would be wrong to give someone good advice???

[MacandHunter]

As a newbie I want to have all of the information I can get up front. As a fish keeper I try to set up my tanks as close to natural as possible and I would want to do the same for any small animal, like hermit crabs. I don't see why it would be wrong to give someone good advice???

Where did I say it would be wrong to give someone good advice? I'm very, very concerned with crabbing information, and that's why I started this thread. Don't put words into my posts that I never said.

My stance is this. I think there are certainly benefits to a 5:1 ratio. But I also think there are benefits to 100% sand. I don't think anyone disagrees with those points. In my mind, 5:1 can come off as a bit trivial. That's 16% of your substrate. When it comes to substrate, there isn't any hard rules on what your substrate must be. There is more than one perfectly fine option, and I think it's important to remember to tell crabbers that when talking about substrate. A lot of people come here and are very stressed, feel in over their head with all the information. A lot of us were shocked crabs required all this care. Some members also have limited resources, either they are young, can't afford much, or both. Because of this I don't think we should present 5:1 as the only viable option for their tank.

When talking about other matters, such as water: can't be from the tap. That's a set in stone sort of matter. However, substrate isn't like that and it's important for newbies to know that crabbers have had years of success with multiple types of substrate.

[Guest]

Okay. I apologize but that was the impression I was getting. I'm glad its not the case.

There are many aspects of husbandry that can be accomplished in multiple ways and while it is daunting to embark on the journey of researching a new animal I don't think it's necessary to stifle any particular opinion, especially on the basis that it might be too much information for the new crabber.

I'm an admin at a fishkeeping forum and when someone is over-whelmed, we just break it down step by step.

[MacandHunter]

I don't want to stifle it. I just want to be sure it's not presented as the only option, when it may be easier to go all playsand for a new crabber. When I post advice to other crabbers, if my way isn't the only accepted way, I make sure to say something like "but others have also had success with blah blah blah." You get the idea. Right now I'm just encouraging others to do the same.