rmcder thank you for taking this conversation in a more positive direction. 12" is average. When they well taken care of they can reach lengths of 14 to 18 inches in an aquarium and possibly live for over 50 years. You are right that this is rare, however this is due to lack of information and improper care. One theory for this is that clown loaches get stunted very easily. From what I have been told by other loach keepers once a clown reaches 4" it should be housed in 48"x12" aquarium. When it reaches 6" it will need to be housed in a minimum of a 48"x18" aquarium. At around 9 to 10" its final home should be in a 72"x24" or larger tank. Another theory for lack of growth in the clown loach is poor water conditions. It is believed that DOC can slow down their growth rate. This theory is held for all fish in general. But given clown loaches sensitivety to poor water and their already slow growth rate it seems rather important to give them the highest quality water. I have found that many of loach keepers who are having the best result do 50% changes once or twice a week. This is what I have been told by people who have had tremedous success with their clown loaches. My own clown loaches have grown from 2" to 6" in 13 months...They are soon to be housed in their new 90 gallon home with 4 new buddies who are currently in my quarentine tank.:dance: I hope one day to house them in a 400 gallon.rmcder said:12" is the figure that sticks in my mind; I suspect they can get larger. Correction?
I don't recall a lifespan number, but I would think that they are fairly long-lived. I would guess five-ten years?
Tank size is going to vary based upon how many are there, naturally, and the length of time. 12" ones in captivity seem to be rare. A single (though you wouldn't want a single) could probably do well in a 36" tank for a good long time.
Water changes? I do 25% a week, which I'm sure is adequate for their needs, but more is probably better.