Donald of Mars Episodes 11-15

A story on building a new colony on Mars and what it will take to live there

Chapter 11 Catfish for Fong

Donald put each of his catfish out of its misery the moment he pulled them from the tank, despite Fong preferring the fish delivered alive. There had been 30 of them, little longer than his middle finger in the tank when he moved in. In less than a month, they were large enough that it had forced him to thin them out. He hated doing that, then thinning them out every month thereafter. Yet it was a necessary part of maintaining the life-support of his apartment. The least he would do is see to it the fish had a quick death.

Keeping the total fish weight between the minimum and maximum range for the system was critical if you wanted healthy plants keeping your air fresh and clean. It was a point they hammered in to you over and over, both during training and during the classes on the trip out. Too few, and not enough plant food in the water resulted in small sickly plants. Too many and the water became toxic. But he got attached too easily. Having more tanks instead of just one as he would in the home he was building would be better.

Underfeeding them was an option many who got attached to their fish went with to avoid thinning them out as often. He considered that possibility when his own system was down to a dozen fish. It came down to efficiency and money. You saved money on food that way, but your output, both plants and fish meat, was also reduced, by far more than what you saved. Yet efficiency also fell off letting the catfish get this big. Growth rates and the percentage of fish food you fed them that turned into fish meat started falling off after one kilo. Some people didn’t care. A single well fed, six kilo catfish kept the plants in Fat Eddies office fed.