Infusoria is a collection of single-celled animals that live in water and it is a critical part of raising the tadpoles of H. boettgeri and H. curtipes.
Without sufficient amounts of Infusoria in the tank, the tadpoles will die within two weeks. The tadpoles begin feeding on Infusoria about 7 days after hatching. They will feed constantly on these microbes for the next 7-10 days. You will see the tadpoles grow quickly during this time, though they will still be very small creatures.
Infusoria is normally present in a well-seasoned aquarium. It's a harmless and even beneficial part of the small ecosystem that is an aquarium. Unfortunately, Infusoria is not usually present in sufficient quantities in a typical aquarium to support the needs of the tadpoles. That's why aquarists who choose to breed Hymenochirus need to add extra Infusoria to the tank.
The article below, by Bill Malay, gives a good recipe for home-grown Infusoria. I have used it and I raised a batch of tadpoles with the culture I grew. It was a messy and smelly job however, and not a project I would recommend for a beginner. Fortunately, there is an alternative to home-grown Infusoria. After my experience with home-brewed microbes, I searched the Web for a source for laboratory-grown cultures. After visiting several Web sites and making phone calls I settled on Blue Spruce Biological Supply in Colorado. The staff is very helpful and their prices are very reasonable. If you decide to purchase your Infusoria you need two components: the culture, and the medium.
Think of the culture as an Infusoria concentrate. The medium is the food that the culture needs to survive and reproduce. You will want plenty of Infusoria on hand to ensure that your hungry tadpoles get all the nourishment that they need. By combining the culture and the medium you can grow more than enough Infusoria for several batches of tadpoles. What follows are instructions for raising a liter of Infusoria and what you'll need to order from Blue Spruce.

Step 1 - Plan Ahead

As soon as you see eggs in your tank it's time to place your order for Infusoria culture and medium as well as the culture and medium for the Daphnia. I recommend using 2nd Day Air delivery unless you're very close to Colorado. By the time your culture
and medium arrive the eggs will have hatched and you'll be ready for step 2.

Step 2 - Get Cultured

When your Infusoria culture and medium arrive you should immediately combine the two in a sterile container.
Keep it warm (70-75 degrees F.).
After several days you should be able to see motion near the surface under 10X magnification.
Read and follow the instructions for your Daphnia. You'll want to get the Daphnia started right away so you'll have plenty when the tadpoles are big enough for "solid" food at Step 4.
Soon you and the tadpoles will be ready for step 3.

Step 3 - Dinner Time

During the week since they hatched, the tadpoles have been busy absorbing their yolk sack,
developing a mouth and intestinal tract, and learning how to swim.
Now they're ready for their first of many meals of microbes.
You should plan on adding Infusoria to the tadpole's rearing net two or three times a day.
Your Infusoria culture comes with a glass eyedropper. Use it to draw the Infusoria from close to the surface of the medium.
Don't be stingy! Add two or three dropper fulls to the rearing net 2-3 times a day. If you have more than 50 tadpoles
in the net add even more Infusoria. Remember, the tadpoles are eating constantly to gain strength and size. They have to become frogs after all, and that takes a lot of nutrition.

Step 4 - Growing Bigger Stuff

After 14-17 days the tadpoles are ready for larger food in the form of brine shrimp nauplii or Daphnia larvae. I raised my broods on nauplii but I don't recommend raising them unless you've done it before. Blue Spruce can set you up with a better alternative: Daphnia.
Daphnia is a freshwater critter that is very low maintenance. In fact they do best if left alone to "do their thing." Plan on getting the Dahpnia started as soon as the tadpoles are on the Infusoria.

Here's what you'll need to get started:

When I ordered my culture I also ordered sterile medium and a 1000 ml. Erlenmeyer flask. An Erlenmeyer flask is cone-shaped with a flat bottom and a short neck.  It's very handy for keeping liquid culture medium because of its design.

UPS had managed to damage one of my containers of medium and I was worried that both might be contaminated. I placed the medium in the flask and boiled it for about 5 minutes to make sure everything was sterilized. Note: I boiled the medium ONLY, not the Infusoria culture.

I covered the neck with a paper towel and let the medium cool to room temperature.  I carefully added the paramecium culture making sure not to get the neck of the flask wet on the inside. I used a large wad of sterile cotton, available in rolls at most drug stores, to stopper the flask. The cotton is a good barrier to bacteria as long as it stays dry. It also lets gasses vent from the flask and allows air in. When I need more culture for the tadpoles I use a sterile eyedropper to move culture from the flask into a small container. You can keep a pure culture for months this way.

Here's a proven method of culturing Infusoria for raising the fry of your egg layers. With this method, a one-gallon culture will support about one hundred young fish until they are past the Infusoria stage. There are ways to raise the fry of egg layers that require infusoria as their first food. One of the main reasons most of the newly hatched fish disappear is that, when Infusoria is fed, there is too much of the contaminated water in the tank, thus killing the fry.

The materials needed are at least two test tubes, a one gallon wide mouth jar, a quart jar to stand the tubes upright in after they are filled with Infusoria water, a syringe bulb with rigid plastic tubing inserted in the open end of the bulb, and some lettuce leaves. The water used is taken out of a tank that has aged water and fish in it. The method used is as follows:

Fill the one gallon jar with the water from the tank, and add 1/2 dozen lettuce leaves. In about 3 days, you will notice a scum forming in the jar. Next, take the syringe and suck the water and scum from the top of the jar, not going in deeper than 1/4". Now take a handkerchief, or bleached muslin, such as an old sheet, and strain the water taken from the jar of Infusoria through the handkerchief into a small jar or cup. This removes most of the scum particles. Fill the two test tubes with the strained water and stand them upright in the jar over night. The next morning you will notice that the Infusoria has risen to the top of the test tubes. Pour only about 1/2 inch of this into a tank that has fry in it and pour the rest back into the Infusoria jar. Do not put an airstone into the gallon jar as this would keep them swirling in the jar and they would not collect in the top in a mass as you want them to.

My theory is that the reason the Infusoria collect in the cultured jar, and also in the test tubes, is that they come up for oxygen. T his amount of Infusoria culture that you have in the jar will smell foul, but that does not harm your fish as you harvest almost pure Infusoria each morning and night until the fry are ready for Microworms or other food. A 1 gallon culture will support about 100 young fish until they are past the Infusoria stage.

Keep looking at the bellies of the fry to make sure that they are full at all times. A magnifying glass is very helpful in checking the young fry and also to see how much Infusoria is already in the tank with them.