I'm glad to hear that you have successfully raised arowana in 60 small tanks. Here are some suggestions for raising arowana:

The small tank of 1.60 is not very big, so it's best to keep only the arowana of 1-2.

2. Arowana needs an aquarium with spacious space, strong water flow and sufficient water depth.

3. Ensure that the water quality is always maintained at an appropriate level, and change the water regularly.

4. Provide nutritious food for arowana.

5. Manually clean the aquarium to prevent excessive waste from being generated in the aquarium.

I wish your arowana health and happiness!