Questions:
Is the BT more tolerant of water issues than the hybrid Donaldson RBT? I know they can survive water temps up to 70-75, love pellets, grow fast, are aggressive, and are widely available throughout the West at least.
If by BT you are referring to brown trout, then yes, I believe they are the most tolerant of any trout species and any rainbow trout cultivars I know of. Our brown trout have a few that hold over almost every year. We've had maybe a couple rainbows hold over in the same conditions. They are more expensive than rainbow trout though. Rainbow trout are typically cheaper than both the brook and brown trout. Rainbows are usually easier to find. Pretty much every hatchery that sells trout will be selling rainbows. Maybe 1/3 to 1/2 of hatcheries sell browns, at least here in the east.
The forage species you recommend, we need to know more. Why are they more suitable to serve as a forage base than other minnows? I imagine they avoid predation better than FHM? They have a lower maximum size than GSH? How about fecundity? We are all looking for self sustaining populations of forage fish - we need to know MORE about these species. For a SMB/YP pond - IS THERE A SILVER BULLET[s]?
All three species are able to handle predation better than FHM. FHM are adapted to life without predators. They live in flooded backwaters that get hot and low in DO where other species would die, they thrive in without that competition. FHM are used by fish farmers because they are easy to raise, reproduce fast and tolerate handling well. They are not raised because of their great attributes as a sustaining forage species. The three species I mentioned are better suited to predation and can commonly be found in the wild in locations where predators are found, unlike FHM. All three mentioned species are raised commercially by scattered fish farms. So they can be procured from a commercial source. However, they aren't like FHM and GSH which nearly ever fish farm raises and sells. Are these silver bullets? Far from it! If you have no habitat for them and have over abundant predators, they aren't going to last... These fish don't have spines, are fusiform and reach maximum sizes in the 4"-5" range... Perfect predator fish candy...
