Would 600 liters of water last you 1000 years?

Answer 1

The consumption of fresh water is necessary for human life, and the question of adequate supplies applies especially to long space voyages (where resupply is practically impossible).

Human requirements are about 2 liters per day, for normal condiitons and normal exertion. So 600 liters, unless recycled, would not last one year, much less a thousand.

Recycling by distillation is only part of the problem : substantial water is lost to the air through perspiration, and some is bound in various body tissues. So 100% recovery and re-use would be extraordinarily difficult. And even with a 99% recovery rate, the 600 liters would be down to unusable levels in less than 100 years (losing 20 ml a day would exhaust 598 liters in 82 years). So the concept of long-term manned space travel is still restricted by this issue, among others, barring some exotic scientific solution.