My daughter has a 2.5 gallon tank for her Betta. I was reading the care guide ( http/www.fishforums.net/index.php?/topic/423362-betta-splendens-caresheet/) and it says to do a 100% water change every 4-5 days in an uncycled tank. uh oh! The tank is just over two weeks old and I havent changed the water. Henry, as he is named, seems to be fine. I am prepared to change out the water tonight...but what is the best safe way to do this? Will the fish be ok moving into a small holding container?