Saturday, December 13, 2014

Baby Russian tortoise care sheet (also for other herbivorous tortoise species)

Baby Russian tortoises have very similar needs to adult Russian tortoises. A requirement of higher humidity and hydration is the main difference. With good humidity, UVB, and healthy food, your tortoise will grow healthily and smoothly. If kept too dry, they will have irregular, pyramided shell growth, and may appear stunted. You can transition to an ‘adult’ RT care regimen once your baby is 4” (10cm) or larger SCL, or 2-3 years old.

When your baby arrives, you can unpack her and set her in a small bowl of shallow lukewarm water – just up to the seam where the top shell and the bottom shell meet - for 10 or so minutes. Then place her in her enclosure in front of a pile of greens. She might eat right away, or she might just explore.
Don't be shocked when you pick her up - baby tortoises have some "flex" in their shells - they are not hard yet like adult tortoises. As they ingest calcium, the shell will harden. It will be fairly hard by 18 months. The belly hardens more slowly than the carapace.
You may observe small, light-colored ‘squiggly’ lines in the tortoise’s shell keratin – these are normal in growing tortoises, and are also a sign that the animal is well-hydrated. Below is a good example of a well-hydrated juvenile Russian tortoise.

(picture used with permission from Siu)

WARNING: baby tortoises are VERY quick! If you are picking up the tortoise, please secure it so it can’t jump/run off your hand.

Russian tortoise babies should be kept in an enclosure that provides room to roam, safety from other pets (e.g. dogs and cats), and holds in warmth and humidity well. For this reason, open-top tortoise tables are often not ideal for the first year, as too much humidity is lost otherwise, and the wood can start rotting from the high humidity.

I personally like the 40gal glass breeder tanks for baby tortoises. I cover part of the top with plexi glass and/or heavy duty foil, to help keep in more of the humidity. A large 40-50gal Rubbermaid bin can be converted into a good baby enclosure as well by cutting holes into the lid for the light and heat sources. I have also used Christmas Tree Storage bins, which are about 2ft x 4ft. They are large enough for the first year or two, but not so large that I constantly ‘lose’ the babies in the enclosure.

A space of 1.5ft x 3ft floor dimension is sufficient for 1 baby. Of course once they get bigger, Russian tortoises need much more space (e.g 3ft x 6ft or more)! Depending on the location of the enclosure, it may be necessary to insulate it – I have taped foil-covered Styrofoam insulation board around 3 sides of my baby tank. The foil bubble wrap-looking insulation works well, too.
This picture shows a creative solution Jessica found using a 54gal Rubbermaid bin. She cut out a portion of the lid, and replaced it with mesh that is held on by Velcro, for easy access, and to keep her cat out. Please note that mesh filters out UVB light, so should not be used under the light source.

More information about lighting will be provided below.

(picture used with permission from Jessica)

For substrate I put in about 5” of ACE brand topsoil, mixed with coconut coir. Any additive free soil without perlite or fertilizers or manure will work, but I have found the ACE brand to consistently be good, and it has a nice consistency. I buy it at ACE Hardware.

The soil should be kept pretty moist, enough that if you run your finger across it, it looks a little muddy. I pack it down enough that it provides secure footing. I place a flat stone under the basking spot, and place a nice little landscape of large and small rocks and plants throughout the enclosure, keeping safety in mind.

I add 20-ish pill bugs into the enclosure from our yard – they come out at night and clean up any poop or left over plant matter!

All tortoise babies should be given constant access to a water dish, so that they can drink and soak as needed. I like to use a 4” glazed plant saucer, with several pebbles or small rocks in it, to help baby get in and out safely. Placing a few rocks around the water dish will also help less of the substrate to be tracked into the water.

Please be sure to read below info about soaking your baby!
(picture used with permission from Jessica)
A baby tortoise enclosure must have UVB light, a basking spot of 95 degrees, a hot humid hide (always 80 degrees, using a CHE and a Hydrofarm thermostat). I outline the specifics of lighting and heating in more detail below.

I place a flat rock under the basking lamp, to keep the basking temperature more constant, and I also place a flat rock somewhere in the mid-section of the enclosure, for feeding on. This will later help keep claws and beak nice and healthy.

You can put a variety of drift wood and rocks, tortoise safe plants (in a pot with additive free soil, or planted into the substrate), into the tortoise enclosure to provide climbing/exploring opportunities. Please be mindful of safety… you don’t want baby to flip over into the water, or get stuck behind something.

In addition to the top soil/coco coir substrate, the baby tortoises have moist sphagnum moss in their hot humid hide (see below), as well as in their favorite hang-out spots, and they dig and burrow extensively.
I use a humidifier (which is optional – it just makes my life easier), and I mist them with warm water every time I walk by, minimum of 4x per day using a pump mister that I got at the garden center (see pic below). Be sure to unscrew the lid after each use to release the pressure… otherwise the pump will leak!

If your tortoise is still a baby or juvenile (under 4") it will benefit from a hot humid hide. I like the plastic shoe boxes from the dollar store. I cut a round or square door hole in about 1" -1.5" up from the bottom.
I fill it with wet sphagnum moss (garden center usually has it near the orchids).
Then I sink the hide into the substrate in the middle of the enclosure, between the hot end and the cool end.  I suspend a 60W ceramic heat emitter (CHE) above it, attached to a Hydrofarm thermostat, with the probe inside the hide. I set the thermostat to 80 degrees F. It is REALLY IMPORTANT to use a thermostat, because otherwise the CHE can overheat the whole tank.

Do you like my turkey-pan cover?!
The CHE that heats the hot humid hide stays plugged in 24/7, and is controlled by the thermostat. The key is to keep baby humid and WARM (since moist+cold is bad). Personally, I prefer a CHE over a heat pad - if you use a heat pad, you still need a thermostat. Burning from below can be severe if the bottom of the enclosure becomes too hot, which is why many choose to heat the hot humid hide from above.
Here is a pic of an example of the hot humid hide box a friend made for himself. 

Raising RT babies in a more humid environment for the first year or two has been shown to give them much more even growth. After the 2nd year (or once they reach 4" SCL) they no longer need nighttime heat. 

Tortoises require UVB light to grow healthy bones and shells, and the very best source of UVB is natural sunlight. Because of this, I try to provide at least 30 minutes of outdoor time to the babies any time it is at least 70 degrees outside.

IMPORTANT: Baby tortoises can overheat very easily! Please never leave them unattended on a hot day. Please ALWAYS place their outdoor bin in a location that is half shaded, half in the sun. If necessary, you can move the bin as the sun moves. Frequent misting will help prevent the babies from drying out. Please also be mindful of other animals or children that might harm your baby tortoise!

I made a planted outdoor rubbermaid bin that the babies spent 30 mins to 3 hours in daily during the Summer. Before adding the dirt, I drilled several drainage holes into the bottom. This helps prevent flooding. The hides are made of plastic flower pots that I cut in half, and layered several inches of dirt over top for insulation. The tortoises really enjoyed climbing the little hills! The water dish is similar to the one in the indoor enclosure. I planted some succulents and weeds in there, placed more moss, and I also spread some of Carolina Pet Supply’s ‘Broadleaf seed mix’ in here. Within weeks it was a jungle in there!
Here is another view of the outdoor tortoise bin, with the lid on. I used a Dremel to cut out part of the lid, drilled small holes all around, then zip-tied hardware cloth (similar to chicken wire, but with smaller holes) into the lid. The locking lid let in the sunshine, but prevented predators from getting in.

One tortoise friend of mine got a little wheeled dolly and placed the baby bin onto it. This allowed them to wheel the bin to different locations in their yard, depending on where the sun was! Great idea, Lynne!

Because lighting for baby tortoises is the same as for adult tortoises, please read the following article first:

Baby tortoises require basking light (95 degrees F at shell height), a UVB source (either separate from the basking light, or an all-in-one MVB such as the Powersun), and a heat source for their hot humid hide. DO NOT use the coil-style UVB bulbs because they are also known to cause damage to tortoise’s eyes.  

When setting up an enclosure, I securely install L-shaped shelf brackets (from Home Depot) onto the wall, and use wire and/or a small chain to hang the basking light and the CHE. I DO NOT rely on the clamps that often come with the lamps.

I have all my lights (NOT the CHE) plugged into a timer to turn them on/off.

Here is a creative solution my friend Bobbye came up with for hanging the lights. She bought the shelf brackets that can be used with a hang bar! I have seen a similar set-up where the tortoise keeper used S-hooks to suspend the lights off of the bar. I love this, because it allows you to move the lights back and forth as needed, and you can adjust the height, too.

(photo used with permission from Bobbye)
For a glass tank, if I am using a tube-style UVB light, I lay the fixture across the top and secure it with duct tape on either end. In a rubbermaid tub, I hang the UVB light fixture by drilling some small holes into the long wall of the rubbermaid, and feeding zip ties through it. The fixture has holes, or you can loop the zip tie all the way around the fixture on each end. The UVB tube should end up being 12-13" above the top of the substrate to be effective. .

Here are a few diagrams, as seen from above and from the side, of possible set-ups:
view from top
View from front

If you plan to use a 40gal glass tank, I would use a 75W household bulb for basking, in combination with the tube-style UVB light. If you are setting up a 54gal Rubbermaid bin, or a 75gal glass tank (or larger), I would use the 100W Powersun MVB, which produces heat and UVB.

I order my lighting supplies online, because this is cheaper than going to a pet store. I'll provide a list below that I've put together. No pressure to get those exact items, I just know that 'new' tortoise keepers sometimes like to get specific information sometimes. 

A regular household light bulb (75W) such as this: with this fixture: Zilla 11596 8-1/2-Inch Premium Reflector Dome For Up to 150-Watt Bulbs, Black (later when you have a larger enclosure you can switch to using an all-in-one bulb like the 100W Powersun, but for the small baby enclosure, 100W ends up being too much). You can also get a fixture at ACE Hardware etc - just make sure the socket is ceramic. 

For the first 2 or so years, baby requires a hot humid hide. I use either a 60W CHE (ceramic heat emitter) like this and you can use a smaller ceramic dome fixture for this, since the CHE is only 60W. Alternatively, you can use a heat pad under the tank where the hot humid hide is. To regulate the temperature, the Hydrofarm thermostat is by far the best: - this is important, because both heat pads and CHE will otherwise overheat. You can use a smaller ceramic dome fixture for this, since the CHE is only 60W.

You also want to get a temp gun so you can check the temperature immediately under the basking spot. Here's the one I have used for several years and love: Etekcity® 774 (ETC 8380) Digital Infrared (IR) Thermometer with Laser Sight, -58~+716°F, 12:1 D:S, Instant-read Temperature Gun, Battery Included

Baby tortoises should be fed the same widely varied diet of edible leaves and weeds and greens and flowers that an adult eats. Special care should be taken to provide maximum nutrition. Here is a link to The Tortoise Table’s printable plant booklet:
The Tortoise Table database is also an excellent resource when checking if plants are safe to feed your tortoise. Please always err on the side of caution!

We are lucky to have weeds here most of the year, so I feed cat's tongue, thistle (sow thistle, mostly), hawksbit, plantain, mallow, grape leaves, and hibiscus leaves and flowers, violet leaves and flowers, sedum, daylily flowers, miner’s lettuce, dead nettle, rose petals (only from untreated, unfertilized plants), turnip greens, and many other plants on the 'safe' list of The Tortoise Table database. I add in some dandelions, but only when there aren't other things. If you don't have access to weeds during the winter, you can feed mustard greens, kale, and collard greens. Opuntia cactus (called ‘nopales’ in Hispanic grocery stores) is high in calcium, and can be added to the diet occasionally. There are many other tortoise-safe weeds that may be available throughout the year that I did not mention here.

I don’t give the babies any lettuce, just because the nutritional value isn't great, but if you find yourself in a bind, that would be an option, too.

I don't chop any of it up, or even tear it up. I like to make them work a little bit to get their food.
A rule of thumb is to give them a pile of food about the size of their shell. As long as babies are kept nice and humid, and the food you offer is healthy, you can allow them to eat their fill - if the food is all gone by mid-day, it's totally fine to give them a second helping.
(a few examples of edible weeds)
I have never fed any factory-made foods (mazuri or Zoomed grassland or other), simply because it's not necessary here, and because I don’t trust the formulation. I prefer to cook from scratch for my human kids, so it made more sense to go the natural route for the babies as well. If you do feed mazuri, I won't judge – please do your research!
I do not feed ANY fruit, and only very occasionally (1x per month) feed a vegetable such as a bit of pumpkin, winter squash, or a bit of carrot, for the vitamin A in it. Fruit is too high in sugar, and not only can become addicting, but it can also harm a tortoise’s gut. It also creates a favorable environment in the gut for parasites (worms and flagellates) to thrive. If I want to give my tortoises a ‘treat’ I give them a flower, or an especially juicy sedum leaf, or a slice of opuntia cactus.

I sprinkle TNT (Carolina Pet Supply) 3x per week, and calcium powder 2x per week. I also have cuttlefish bone (which is available in the bird aisle of the pet store) in there, to which I have seen them help themselves. The babies also have a home-made calcium block available in their enclosure, which they like (instructions:

Baby tortoises have less body mass, and as a result, are more prone to dehydration. Even if babies frequently self-soak in their water dishes, it is recommended to soak them every day when they are very small, and every other day once they are a few months old. Tortoises need water to maintain good hydration and for proper organ function.

A soaking container should have tall enough sides that your tortoise can’t climb out. The water should be lukewarm and shallow, just about up to the seam where the top shell (carapace) meets the bottom shell (plastron).
Some people put a washrag into the soaking container, to provide a little more footing to the tortoise. A soak should last about 20 minutes – you may need to change the water if it gets too soiled, or too chilly.

We soak our baby tortoises during breakfast. This is fun for the kids (‘breakfast buddies’!), and it also makes it easy for us to keep an eye on them to ensure they don’t flip over and/or drown.

Tortoises will often poop during their soak. They will also often release urates – which are a white creamy (or lightly granular) substance. Both are perfectly normal.

Several people have asked me what my daily routine is with the tortoises, since it does take a little bit of time to care of tortoises properly. I have found that associating tortoise care with our regular daily activities makes it easy to find a good routine.
In the morning the lights turn on by themselves, controlled by a timer. After getting dressed, I get the babies and their soiled water dishes out of their enclosure. I place the tortoises in their soaking containers, and I clean the water dishes. The baby tortoises soak while we eat breakfast. After about 20 minutes (during which I’ve also fixed school lunch for kids, and made sure they brushed their teeth etc), I put the babies back into their enclosure. I give them a nice big pile of weeds (sprinkled with TNT), and mist the enclosures thoroughly with warm water. Then we go about normal morning activities.
Mid-morning my youngest and I usually go outside on a walk or into our yard to pick weeds for the next day. When we get home, I mist the babies again, wash and pack up the weeds, and continue with our day. Sometime in the afternoon I check on the babies, mist them, and if they have eaten all their food, I give them a second pile of weeds. Before starting dinner, I usually mist them one more time, and the lights turn out around 7pm.
I weigh them about once every 2 weeks. The pill bugs take care of most of the clean-up in the enclosures. As needed I replace sphagnum moss, rearrange tortoise furniture (if e.g. they outgrow things, or they climb on things dangerously), add new plants, etc.

A note: Our tortoises are used to normal family activities around them. Their enclosures are in our living room, and the kids play around them, are loud, and watch them. They sit on our dining table for their morning soak, with little faces peeking down at them. However, I minimize how much we actually touch and handle the tortoises. I believe that observing them in a natural habitat is more beneficial than constantly actively interacting or playing with them. As I check on them throughout the day, I might place one of them that I’ve noticed has been sitting on the cool end for a long time into the hot humid hide. But for the most part, I just let them do their own tortoise thing. Please don’t handle your baby too often – this can cause stress, which can lead to them eating less, which can slow down their development.

Tortoises, especially Russian tortoises, are very territorial, and can become violent towards others of their kind. Sometimes bullying is more subtle, but just as deadly. I do not recommend keeping more than one tortoise in an enclosure once they are older than two years. I definitely do not recommend keeping a baby tortoise together with an adult tortoise!

When they are babies, you can sometimes get away with keeping multiples in an enclosure that is large enough. However, please keep a constant watchful eye on them, to make sure both are thriving!
For more reading on the hazards of keeping 2 tortoises together, please refer to my blog post:
If you have the resources to provide individual set-ups that are large enough, and you have the time to care for multiple tortoises… obviously there is no reason not to have more than one tortoise… just don’t house them together as adults!

Disclaimer: This care sheet has been compiled based on information I have gained from more experienced breeders/tortoise keepers, such as Melissa, and Tom, Gary, Tim, and others (THANK YOU!). There are excellent care sheets available e.g. on the Tortoise Forum ( I have written this care sheet because I know some of you want more detail, and so that you will have something printable in hand, with detailed pictures.

Resources for further reading:
Melissa’s Russian tortoise care sheet, posted on the Russian Owners Facebook group (you may have to join the group to view it):
Please feel free to join the Facebook group “Russian Tortoise Owners”
Joe Heinen’s page on RTs:
The Tortoise Forum:
Shelled Warriors:
The Tortoise Table (info on plants):
The Tortoise Trust (good info on hibernating etc.):
Carolina Pet Supply: (to order TNT and seed mixes from)

Please never hesitate to ask questions!

Sunday, November 9, 2014

Lady's first egg hatched today!

Lady's first egg finally hatched! She is a healthy and perfect little Russian tortoise hatchling, and weighs 16g.
Finally out! 
This wee baby had NO hurry to get out of her egg. She didn't pip until day 68, and then she sat in there, looking out of the little hole she had made, for 3 days! When we came home from church today, she was finally out of her egg.

The lopsided shape will even out in a few days
She was rolled diagonally inside the egg, so she is still quite lopsided, but that will even out as her shell hardens, and she'll be a normal little oval baby. Look at her little nuchal scute (it's the one right above her head) - it's split in half, making it look like a perfect little heart!

16 g of pure cuteness
She is dark, and very domed. Her Mom and Dad are both sunflower yellow with black markings, and very domed, so she's going to be a beauty!

Saturday, November 1, 2014

Dissection of a failed tortoise egg

Yesterday my son and I dissected a Russian tortoise egg that had stopped developing and dried out. Inside we found moldy icky stuff, but also a tiny blue tortoise fetus about 1.5cm long. It was truly amazing to see how fully formed it was, with tiny claws, little scales, closed eyes, a stubby tail, a little beak, and all the scutes on its shell.

My fingernail and the foot of a tiny penny-sized tortoise fetus from a failed egg.
Since not everyone enjoys reading about or seeing pictures of this kind of thing, I am not creating a blog post about it here. However, if you would like to see pictures (no gore, just a tiny fully-formed penny-sized blue tortoise fetus), here is a link to my article on the Tortoise Forum: "Egg dissection"

Thursday, October 23, 2014

Pip pip pip! First Fall Russian tortoise baby hatched!

I am so excited to share with you that Mila's first egg hatched last week! This was the first time she ever laid, and the egg was quite large, at 30g. 63 days incubating at 89 degrees F later, the egg pipped (which means the shell started to crack where baby was pushing through).

Do you see the tiny pip there on the left side of the egg?
Tortoises, just like many other animals, hatch at their own pace, some faster, some more slowly. It is super important to let them come out on their own. If rushed (helped), a weakened, unmotivated baby may be the result, or the yolk sac may not be fully absorbed.
For this reason, as hard as it is, I just moved the pipping egg into a separate container in the incubator, with a moist paper towel, and then left it alone.

1.5 days later, the head and front leg are out
This baby took its time to hatch: one and a half days later, a tiny head and an arm were hanging out of the egg. It was responsive to light shining into the incubator, and was clearly breathing, so I continued to just leave the wee tyke alone.

48 hours after first pip, Mila's baby is out!
Finally, 48 hours after pipping, Mila's baby finished hatching and burst out of her shell! Looking at her through the window of the incubator, she looked very fat and more domed than Timmy's Spring hatchlings.
Mila, the baby's Mama
As a reminder, I posted a picture of Mila above - she has a pretty greenish shell that is unusually domed. When I got Mila's baby out of the incubator to give her a quick look-over, I could see that she resembled her mother a lot!

Hatched Oct. 15th, perfect, fat, and weighing 20g!
 This wee girl surprised me with her size - at 20g she is quite large for a Russian tortoise hatchling. She has fat rolls on her legs, she has a double chin, her shell is very domed, and my favorite part: she has a handlebar mustache!

A pretty greenish-brownish shell like her Mama
I am so proud that Mila is a Momma now. I am also happy (and a little surprised!) that Mila's huge, very elongated egg hatched out a perfect baby.

Cute little belly, with the yolk sac mostly absorbed
Baby's belly markings look like a clover leaf. Her yolk sac was mostly absorbed when she hatched - confirming that she knew what she was doing when she waited to come out of her egg.

Having her first soak
After 4-5 days in the incubator with daily soaks and mistings, I moved the baby into the baby enclosure. She is a little go-getter, very quick, and very curious. I see her scrambling all over the enclosure, burrowing down into the moist moss at night and several times throughout the day. She also takes teenie tiny bites out of tender greens.

Photo shoot with a dandelion
We got lucky last weekend with some amazing sunny weather, so I brought all the tortoises outside for some time in the natural sunlight. I took some pictures of Mila's baby next to a dandelion. Cute little green fatty!

So tiny, but already on the go! was hard to get a good picture of her, because she was moving around so much. "Here I come, world!" she seemed to be thinking. 

Sunday, October 19, 2014

Updated Baby Russian tortoise pics

The Russian tortoise babies are getting so big! Duchess hatched at the end of May weighing 14g, and now weighs 59g at not quite 5 months old. I thought you might like some pictures of Duchess (Timmy's Spring baby #2), who is the hatchling I'm keeping.

Stay tuned for baby pictures of the brand new hatches... coming VERY soon!

Saturday, October 4, 2014

How to make home-made calcium blocks for tortoises

Tortoises need calcium in order to build strong bones, a strong shell, and healthy organs. Ideally, they are fed a widely varied diet of nutritious weeds and dark leafy greens that have high levels of bio-available calcium in them. Adding a sprinkling of a healthy plant-based supplement such as TNT can help significantly. However, sometimes a tortoise's calcium requirements go beyond what is found in the plants we can provide. 
Some tortoise keepers rely on sprinkling calcium powder on tortoise food. However, this has the danger of causing a dosage beyond what a tortoise needs, and may actually cause health problems. For this reason, I like to provide healthy tortoises with calcium sources that they can help themselves to, as needed. Tortoises seem to have a good instinct about when their body needs more calcium.

Some tortoises readily eat cuttlefish bone on their own.
Cuttlefish bone (found in the bird aisle of most pet stores, or available in bulk online) is a good option. However, not all tortoises seem to care for cuttlebone. Quarry chalk is a good source of calcium. It is widely available in the UK and some other countries, but is hard to come by here in the US. Finally, man-made calcium blocks are another good source of calcium. Some such products are available in the pet trade. However, I have found them to be ridiculously expensive, and they often have undesirable ingredients such as sugar or artificial dyes and flavors. For this reason, I did a little research, and decided to try making my own calcium blocks.  

The home-made calcium blocks are tortoise-approved!
After seeing how ridiculously easy it is to make the home-made calcium blocks, I wanted to share the recipe and procedure with you, so that you and your tortoise(s) may benefit from it as well. 

First, you need to decide on the calcium source. Food-grade calcium carbonate (CaCO3) is one good option, sometimes called Limestone flour (available e.g on Amazon). Another, more affordable and more easily available source is so called Agricultural Lime (CaCO3) - I got it at our local feed store for $8 for a 50lb bag! Agricultural lime is produced by pulverizing limestone or chalk, and is commonly used as a soil amendment. Please make sure to read the label CAREFULLY: you want to make sure that it not so-called hydrated lime, that it does not contain Magnesium Carbonate, and that it does not have any other ingredients and impurities in significant amounts. Here is the kind I bought:

One of many good options
The only other ingredient you will need to make lime blocks is water.
For tools, you will need:

  • a large mixing bowl 
  • a sturdy spoon to mix with 
  • and some kind of mold that will withstand 200 degrees F (93 degrees C). I used a silicone muffin pan that I got at Goodwill for $2 
  • an oven, pre-heated to 200 degrees F (93 degrees C)

It took a little bit of mixing and adding to find just the right consistency. Here is the ratio of ingredients that I found to work best:
  • 1.5 cups of warm water (H2O)
  • 7 cups of CaCO3 powder (Ok, sue me; I used a liquid measuring cup to measure the dry powder, which I know is a no-no in cooking... but in this case it worked fine, since I was just aiming for keeping track of the ratio that worked)

    NOTE: Today I made the calcium blocks again, and this time it took 4.75 cups of CaCOand nearly 1.5 cups of water. You may have to experiment just a tiny bit - the mixture should be mixable with a bit of muscle, but not all crumbly. It definitely should not be wet or soggy.

Calcium Carbonate powder
First, I measured the Calcium Carbonate Powder into the mixing bowl. Then I made an indentation into the powder, and slowly poured the warm water into it. Then I very carefully stirred the mixture, to minimize clouds of powder flying up and all around. The mixture quickly gets very thick, so you really do need a sturdy spoon made of metal or wood. A spatula didn't cut it.

Yum! Calcium paste!
Keep on mixing until there is no more liquid on top, and no more pockets of powder at the bottom. It will get progressively tougher to mix, and will start looking like mortar or thick plaster of Paris.

Next, spoon the Calcium Carbonate + water mixture into the molds you have chosen. The amount I made was exactly the right amount to fill all 12 wells of the muffin pan, plus 1 small cup.

NOTE: Please DO NOT dump excess slurry down your drain. It can clog your drain and/or wreck your in-sink disposal. I took the bowl outside and hosed it down. It is perfectly safe just to dump it onto your garden or your lawn. 
In fact, if you don't have a lot of tortoises, and don't want to have the remnants of a 50lb bag (minus 7 cups) of agricultural lime sitting in your garage... just spread the rest into your lawn, or dig it into your flower beds or raised garden beds!

Soon-to-be Calcium blocks
Next, carefully place the mold into the oven. I used a cookie sheet under the silicone muffin pan since it is a bit wobbly. Set the timer to 1 hour.

Bake the calcium cakes
After 1 hour of baking, open the oven door and carefully pull the oven rack out far enough that you can safely touch the calcium cakes. You will notice that water has risen to the top of them. Use a paper towel or napkin to wick off the excess liquid. This will significantly cut down on the drying time.
Bake for another 2-3 hours, depending on your oven. I checked every hour to remove more liquid, and after a total of 4 hours, they looked completely dry, and had shrunken in the molds.

Carefully remove the mold(s) from the oven, and place somewhere to cool down. This took a long time. I used our handy dandy infrared thermometer to check the temperature of the calcium blocks, and waited for them to almost be cool enough to touch.
Once they are cool enough, carefully remove each calcium block from the mold, and place it on a cookie drying rack. They should come out easily. I let them sit like that overnight, just to make sure all the moisture had dried out.

12 beautiful calcium cupcakes.
The next day, I put one of these beautiful calcium cupcakes into each of the tortoise enclosures, and packed the extra ones into ziploc bags for later use. Within minutes of placing the cakes into the enclosures, the tortoises congregated around them, and took a few nibbles. Pretty soon, they were sporting cute little calcium mustaches... 

Jill approves.
The part that really made my day: Amber, my XXL female Russian tortoise had just laid eggs. She has been stubbornly refusing to eat cuttlefish bone, and does not eat weeds if I have sprinkled them with calcium. However, by evening, her calcium cake looked like this:

Amber loves her calcium cupcake!
I hope you have fun making your own calcium blocks, and that your tortoises enjoy them as much as mine do! Please keep in mind that in order to properly absorb calcium, a tortoise needs UVB to produce vitamin D3. You can read a little more about this HERE.

Ps: When you mist your enclosures, please avoid spraying the calcium cakes too thoroughly (you might take them out briefly), because otherwise they may disintegrate.

Pps: You might experiment with mixing in ground up weeds, or a little bit of carrot juice for a nice orange color... however, my tortoises (even the ones who NEVER eat cuttlefish bone!) heavily approved and helped themselves to these calcium cupcakes within minutes of placing them into each enclosure.

Ppps: I am not the inventor of home-made calcium blocks. There are several conversation threads on the Tortoise Forum (e.g. HERE and HERE) that mention them long before I ever thought of making them. They don't however, mention the exact ratio of water and CaCO3 (Calcium Carbonate) that works best.