The basic reply I will give, is that it depends on water quality, conditions for growth in a suitable pond. In regards to your small tank keep an eye on water parameters while they are in such a small volume of water.They need increasing volumes of water as they grow. Assuming they are young (under 2" ) they should be growing if your feeding & keeping a good temperature (17 to 24 degs C) through the winter, after next May then place them in a suitably large pond. At least 200 galls per fish, so also allow for adding more fish, over 3000 galls would be a step forward for your plans. In the right conditions 30, 40, 50 years can be exspected, have been known to live over 200 years. In the meantime read and learn lots, and plan that new pond well.
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