Bruce, you may want to cut back on his food. Like "The Blob," this fish grows in direct proportion to how much it eats. I think 20" is max, but I may be wrong.
I use Aquadine Duraflakes, freshwater formula. You can order it from Pet Solutions. I am a dealer, so I get mine by the case from the factory in California.
I believe New Life Spectrum would be just as good. I've used Hikari for more than two decades, and its a fine food as well.
Again, thanks for giving him a good home.
BTW - I doubt he is much more than 3-4 years old. I believe you will have him for at least another 10 years - probably longer. :lol: