To answer your question, I got this from gamefaqs
Open the spoiler
<div class='spoiler_toggle'>Spoiler: click to toggle</div><div class="spoiler" style="display:none;">After this Ganon appears and goes, along with you, to the Pyramid of Power for
the final battle. Before jumping into the hole you might want to return to the
Light World and go to the witch's hut to buy four Blue Potions, just a
suggestion. Maybe two blue, two red, whatever. Ganon is a reasonably
difficult boss, but I guess that's because he's the boss of the game. With all
those potions it's going to be pretty hard to lose. What you're trying to do
pretty much is be really offensive for this battle. A lot of the time if
you're trying to avoid all his hits you'll find yourself running around too
much and never attacking. I say to hell with being hit, use your judgment and
try to dodge, but if you're going to be hit, then fine, it's worth it to hit
him a bunch of times. Just stick with your sword for the beginning of the
battle. His only real attack is throwing his trident. After awhile he begins
using spinning fireballs, stay in the middle of this and keep attacking. The
hardest attack to dodge is the phoenix that flies around directly at you.
Don't worry too much about it and keep attacking with your sword. After awhile
he will mention something about the dark and that's your cue to equip the Fire
Rod and hope you have lots of magic power. When it goes dark use the Fire Rod
to light both torches at the bottom. At this point you have to dodge the
phoenix and hit the boss once, it's harder than it sounds. After hitting him
once his colour will change to blue as if he is frozen, switch quickly to the
Bow and fire an arrow at him. With Silver arrows, it shouldn't take more then
four or five shots to eliminate this boss permanently and end the game.</div>
I've been meaning to get that game for awhile.
