I posted this on your last thread when I miss read the title
It is still my little Colombian tetra I have named Survivor. I moved a plant out of one of my tanks that has Colombian red fins in it to a non heated goldfish tank.The tank was drained down to on an inch of water in order to move it. Then I filled it with tap water and moved the gold fish in. A few weeks later I see a little fish swimming around couldn't even tell what it was. 4 months later I have a good sized Colombian Redfin swimming with two fancy gold fish. It even survived a battle of ich I received complementary of one of the goldfish I bought.
This little guy is going against everything I knew about fish. I hope he will become the oldest tetra ever