Thai micro crabs are fully aquatic freshwater crabs that can easily be kept in nano tanks.
This article will describe my experiences keeping a group of six Thai micro crabs in a 2-gallon aquarium and how to set up an aquascape for these miniature invertebrates.
For those who enjoy watching a tutorial, I’ve created a video on how I set up a mini aquascape for the Thai micro crabs, and I’ve also included footage of their behavior and interactions with one another (they are not entirely passive!) :
And, for those who want to see the steps written out with a little more detail, with links to the equipment, hardscape, and plants that I used, keep reading.
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Step 1: Select a Tank & Place It on a Sturdy Surface
Thai micro crabs are less than 1 inch (2.5 cm) in size fully grown, and they are shy.
This means you won’t see them unless you set up an aquarium that limits where they can hide.
I find that a 2 or 3 gallon aquarium is the ideal size because the crabs are confined to a small surface area and the water volume is still enough to maintain stable parameters.
The tank in this video is a 2-gallon, vertical rimless tank, which further limits floor space but allows for creative ways to aquascape with taller plants.
Keep in mind that small tanks require careful monitoring and consistent water changes to maintain water quality.
These crabs produce very little waste so ammonia spikes from waste is not really a concern, but something like leftover food could degrade water quality if left for a significant period of time.
So, if a 2-gallon tank sounds stressful, consider getting a 3-gallon or even a 5-gallon rimless tank for your Thai micro crabs.
But, because I enjoy keeping nano tanks, I selected a 2-gallon tank for this build, even if it means a little extra work.
If you want to use the exact same tank for your build, here it is:
Step 2: Get a Quality Aquarium Light
I’ve chosen an aquarium light specifically designed to aim the majority of the light straight down, which is great for a tall, portrait style aquarium.
You could also use a desktop lamp and position it over the top of your aquarium.
Just make sure you are getting a light that is strong enough to grow easy aquarium plants (I avoid kit lights but even those can grow moss and Anubias).
You can find the light used in my Thai micro crab aquascape here:
Step 3: Choose Your Substrate & Fill an Aquarium Filter Bag With Gravel/Substrate
The next thing you need for your tank is substrate.
Because we are using live plants in this aquascape, I prefer to use a substrate that contains nutrients that aquatic plants can use to thrive.
One of my favorite substrates for planted tanks is Fluval Stratum (Eco Complete is a great alternative if you can’t find any Stratum).
Fluval Stratum is composed of volcanic dust particles into tiny little spheres.
I love the look of Fluval Stratum and it’s super easy to secure plant roots in; I find that fewer plants become dislodged during water changes compared to my other favorite substrate, Eco Complete.
Once you’ve picked out your substrate, fill an aquarium filter bag with that substrate (gravel also works) and place it at the bottom of the tank.
The goal is for the back of the tank to be higher in elevation than the front of the tank.
Step 4: Cover the Filter Bag With Substrate
Cover the filter bag completely, and examine the tank from all angles to make sure you don’t see filter bag mesh poking out.
Creating a hill at the back of a small tank can be tricky because it’s easy to go overboard on the amount of substrate.
Adding too much substrate can decrease water column when you fill up the tank (which is not ideal in a tank as small as a 2-gallon); try to use just enough substrate to cover the filter bag but not too much that.
Step 5: Add Seiryu Stones
For this aquascape I decided to use a couple pieces of Seiryu stones, which are popular among aquascapers.
I positioned the Seiryu stones in a horseshoe shape, which helps creates a sense of depth in the tank.
I considered using Dragon stone in this aquascape, but I find that dragon stone looks more impressive if it has room, or negative space, surrounding the stones, and there is simply not enough space in a 2-gallon tall aquarium.
Step 6: Add Aquatic Plants
In this aquascape I used the following aquatic plants:
2) Alternanthera ficoidea ‘Red’
3) Moneywort (Bacopa monnieri)
5) Lobelia cardinalis
6) Susswassertang
The goal was to select hardy plants that would not grow too quickly and overwhelm the limited surface area at the bottom of the 2-gallon aquarium I’m using.
Step 7: Add Driftwood
Besides adding interest and aesthetic appeal, driftwood provides a number of benefits in aquariums.
One of those benefits is serving as a surface for beneficial bacteria, algae, and other microorganisms to colonize (all of which help enhance water quality).
The driftwood I chose for my micro crab aquascape was a slender piece of spiderwood.
If you want to learn more about the different types of woods that can be used in aquariums, check out my article on the best aquarium driftwood.
Step 8: Place a Protective Piece of Plastic Over the Setup & Add Water Slowly
When it’s time to fill up the tank, I always advise to add water slowly by deflecting the flow with a piece of plastic or bubble wrap.
For small tanks, like a 2 gallon, adding water at a painfully slow rate is important if you want to preserve the layout of your plants.
This 2-gallon aquascape has been established for a while now, and I still manage to unearth plants when I’m doing a water change.
So, be especially careful and try to direct the water flow on top of a rock or something that sits above the substrate.
Step 9: Add a Heater
Small tanks do best with small heaters.
For this setup I used a flat heater intended for betta fish or shrimp tanks.
The advantage of using a flat heater is that it is easier to conceal with plants and/or hardscape.
Step 10: Acclimate & Add the Thai Micro Crabs
Like other freshwater invertebrates, acclimating the Thai micro crabs to the temperature and water parameters should be done with care.
Drip acclimating is a great option, but my favorite method for shrimp, snails, and crabs is to transfer them to a small Tupperware container (with the water they came in), and then add small scoops of tank water every 10 minutes or so, for a duration of 30-40 minutes.
Note: don’t make the mistake of adding the crabs to your aquarium before its fully cycled. A good rule of thumb is to wait for algae to grow in the tank before adding any crabs or other invertebrates, but test your water before introducing any animals to your aquarium.
Thai Micro Crabs vs Freshwater Shrimp
Both Thai micro crabs and freshwater shrimp, like cherry shrimp, are ideal for smaller tanks between 2-5 gallons.
The main differences between these two crustaceans are behavioral.
Thai Micro Crabs are extremely shy and cautious, often pressing their bodies up against rocks and wood and remaining motionless for long periods of time.
Cherry shrimp are also cautious, but not to the degree of Thai micro crabs.
While my Micro Crabs prefer to move around the tank after the light goes out, my cherry shrimp constantly foraging for food in the open at all hours.
Another difference between cherry shrimp and Thai Micro Crabs is that cherry shrimp are excellent algae eaters and will keep plant leaves free of some of the more stubborn algae types.
Thai micro crabs seem to eat algae but not at the speed that cherry shrimp do.
For Thai micro crabs, algae is an afterthought whereas for cherry shrimp, it’s their main interest.
Conclusion
I hope you enjoyed learning about my Thai micro crab aquascape.
These invertebrates are incredible interesting, but may not be right for people hoping to see a lot of activity or behavior.
But, these may be perfect for someone who enjoys playing “Where’s Waldo” with their crabs, while enjoying how calm and peaceful these creatures are.
If you want to learn more about keeping invertebrates instead, or in addition to, tropical fish, check out my articles on freshwater shrimp.