Use the frog lure. Be wary; the timing needs to be much more exact, and you need to wait a split second before you press the button to catch it. Practice using the lure on other fish to get the hang of the timing.
Go to the spring in lake hylia and go a little to the right and go to the stick that's connected to the ceiling and cast your rod. you should find the loach there.
iv'e beat and gotten everything in that game MILLIONS of times, but i havn't played it in a while so i need to know what exacly the loach is. as in, is it a fish, or a lure? i HAVE caught every fish so if you need to know, I'll be more than happy to tell you.
It's a hylian loach.
winter
To catch the Hylian Loach in "Ocarina of Time," go to the fishing pond in Lake Hylia and use the longest rod available. Equip the sinking lure and cast it into the water, ensuring it sinks to the bottom where the loach resides. Patience is key; wait for the loach to bite, and when it does, gently reel it in without using too much tension to avoid losing it. If you're having trouble, try using the bait method, which can also increase your chances of a successful catch.
If you catch the biggest fish as young link, you'll get a piece of heart. If you catch the next biggest fish as an adult, you get the golden scale, which lets you dive 9 units (meters?). If you catch the legendary hylian loach, which looks like an eel, as adult link, you get 50 rupees.
Spined loach was created in 1758.
Keith Loach was born in 1975.
Barred loach was created in 1846.
Jack Loach was born in 1942.
Horseface loach was created in 1854.
Stone Loach was created in 1758.