BioTioo Technology: Construction, Material, and Mechanics

The Stirrer: What It Does and What It Doesn’t

The agitator of the BioTioo is firmly integrated into the removable solid waste container and mixes every addition there with coconut fibers: This one component is what turns the dry toilet into a composting toilet. It performs three measurable functions: drying, mixing, and reducing volume. It does not perform a fourth: producing finished humus. We set this boundary from the start, not only at the end. Mixing creates drying Moisture is the enemy in every solid waste container because what remains wet smells. The agitator counteracts this through three linked effects: it breaks up clumps and thereby increases the surface area where water can evaporate; it completely coats every fresh addition with absorbent coconut fibers instead of just sprinkling them; and it levels the cone that otherwise piles up in the center of the container. Without this mixing, only the top layer covered with fresh litter dries; underneath, the core remains moist because the litter lying on top rather than mixed in does not reach the moisture, and this residual moisture keeps the odor alive. Because the agitator mixes every layer anew with each use, the contents dry evenly, the volume decreases, and the container holds 20–30 uses per filling (15 liters nominal, about 12 liters usable; for two people about 14 days). You can drive the agitator shaft by hand crank, ratchet, or motor; the crank operation works completely without electricity (fully functional without power). Regular household toilet paper is allowed inside; the agitator shreds it during mixing. Which litter best supports mixing is shown in the litter comparison; the separation of urine and solids itself is explained in the basic article How a Dry Toilet Works. Pre-composting, not finished humus Only the first stage of decomposition takes place in the solid waste container: drying, mixing, volume reduction; finished humus does not form there. We deliberately call this step pre-composting and stick to this narrower term, even though more is promised elsewhere. No container of this size composts solids into soil in days because real decomposition requires time, microorganisms, and a stable environment, three conditions that a mobile 15-liter container does not meet. What pre-composting delivers instead is still the crucial step: after 20–30 uses, the contents are dry, crumbly, and look like forest soil. On your own compost heap, it then needs about another year of further decomposition before it becomes soil. On the road without your own compost, the appropriate disposal method depends on the region and situation; we deliberately do not make a blanket statement about this. Container and agitator come out together For us, the agitator is not a fixed part of the toilet but part of the container. We filed the patent for this in autumn 2019 with the German Patent Office; today the agitator is patented: a removable solid waste container with an integrated agitator and a precisely fitting guide into the housing. To empty it, you lift the container out with one handle; the housing remains installed, so no service flap is needed. For cleaning, you remove the agitator with one hand and rinse both parts separately. The trade magazine Reisemobil International called this a “clever solution” on 19.11.2024: you don’t have to disassemble the entire housing to empty it. Weekend campers don’t need an agitator For two or three days on the weekend, the bag operation is the simpler solution: insert a bag, take a trip, remove the bag. No litter routine, no cranking, but bag waste with every change. We don’t take this decision away from you; we lay it out openly. The agitator is worthwhile instead for longer trips and off-grid stays: you empty less often, are no longer dependent on bag supplies, and have dry container contents instead of full bags. For campers who are on the road every weekend, the agitator version is still an option. The price is a small routine: a few turns after each use, litter on board, the coconut brick needs hot water to swell, and an additional moving part with more surface area than an empty container alone, which occasionally needs washing out instead of just wiping. Because the agitator and container can both be separated without tools, this results in a washing step at the sink, not a disassembly project. The direct comparison of both operating modes on the same housing is made in Dry Toilet with Bag or Compost. Those who want to give up the crank routine can choose the motor; how it works with the hand crank as a fallback is explained in the factory note on the TiooMotion motor system. Availability The patented agitator is included in the R, RL, and RL-Motion variants; every BioTioo 2.0 can also be switched from bag to compost operation via the container module. For tight bathrooms, there is the ratchet with a switch lever for right and left rotation; everything is developed and manufactured by us in Überlingen on Lake Constance. We offer a 3-year warranty on the bowl and lid, plus a 60-day return policy. All configurations are shown in the overview of composting toilets.