Unfortunately I cannot get a larger tank. At least not for a long while. The loaches were purchased for me as a gift and the information we have seen thus far is that in captivity they RARELY get over 7 inches in length which is why they are so infrequently bred in captivity; they simply do not get large enough. In the WILD it is not uncommon to see them reach the sizes indicated in the article referenced.
My tank is a breeder style, larger surface area than the standard style tank and is not stocked to capacity. They should be fine. I should one day be able to obtain a bigger tank but to be honest my 30 gal breeder has more surface area and can take bigger bio load than the standard sized 55 gall.
I maintain the tank with weekly water testing and water changes to maintain a great water quality and do frequent gravel vacuuming to remove
detritus.