How long to powerfeed undernourished kuhli loaches?

[MultipleTankSyndrome]

Some of the kuhlis I have are on the undernourished side - aka the only time to powerfeed any fish. Tropical Krill/Discus Gran, bloodworms, brine shrimp, and mysis shrimp ought to be good choices (with appropriate attention will be given to water quality while this is being done, of course).

I should note, though, that I'm keeping them at 21.6-23.3 Celsius (within the range recommended by Seriously Fish). They aren't decreasing their activity or appetite from when I kept them at 24-28 Celsius (as most do), but still I suspect bulking up will be slower than at the latter temperature, so it is a caveat to my question.

For those who have powerfed undernourished kuhlis back to health with similar foods to these, how long do you think it might take at the temperature of my tank? Asking to know a ball park, thanks!