The top-left pot has a full refill. Anyway, continue right. Head through the bottom door and turn the sphere blue. Head back out, right, up the stairs and through the locked door. Open the chest for a Small Key and continue left and upwards. Go through the door.
Make the sphere blue. Place a bomb in front of it, head beyond the pegs, and then continue down when the pegs lower. Unlock the door and head right for the Map. Go back left, make the sphere blue, return to the Map room and head up the stairs to 2F.
Lift the pots for a door-release button. Use the Cane of Somaria to make a block to hold the button down. Continue left. Kill the bomb-bugs. Hookshot your way across to the chest if you want 100 Rupees (line up with either of the two blocks to do so), or otherwise just head north.
In this room push the right-hand block down the hole and make your way right. Hookshot to the right. Go up and Hookshot to the right for the Compass. Hookshot back, head left, and go through the door.
Go up, right, down, down, down and right. There's 100 Rupees in the top-right and bottom-right corners, if you want them, and you can bomb the bottom-left wall for another hundred. Anyway, head right. Open the chest for aSmall Key and go through the door.
Go down, right, up, right, up, left, down, left, up, right, and up the stairs. Head down and then right (use the ramming-bounce trick to cross the gap on the way if you want 100 Rupees). Head up. Here, bomb the right wall if you want 400 Rupees, otherwise run up to beat the falling tiles and then go up the stairs.
Here the top-right pot has a full refill. Use the Cane of Somaria to make a platform below, then Hookshot across to the right and go through the door for the Big Key. Hookshot down to the lamp afterwards. Continue right.
Time your actions to pass the laser eyes. Bomb the left wall if you want 400 Rupees, otherwise head right.
Collect the fairies if you want them, otherwise head up to fight Trinexx. Hit the blue head with the Fire Rod and the red head with the Ice Rod. You can either hit them with the sword (one hit each) or keep blasting with the Rod (three more hits each). After this happens Trinexx collapses and turns into a snake. Hit the flashing part three times to kill him. Collect the Heart Container and Tablet then go north and up the stairs to 5F. Head south and out the door.