I have two 20+ year old loaches. I came on this site to see how long they live. I've had aquariums all my life, but never have any fish lived through what these two have. I know you guys are going to fillet me, but I have had them in a 5 gallon tank all this time. I got them when I was young, they've been with me while dating my husband, then 20 years of marriage. I love these guys so I haven't wanted to move them from their tank because they seem to be doing ok. Strong, healthy, sometimes they click at eachother in the spring. But they are about 3 maybe 4 inches long, still rather small for what I know they can grow to. There have been frogs in their tank, Siamese fighting fish, invisible catfish, lots of bettas. It's been just the two of them for awhile lately. Now that I know they may live to be 50, I wonder if they are happy? I'd hate to move them and have them perish. Any suggestions?