If always used FE3CL, if I remember that right.
I always also used positive 20 to get the tracks onto the board. Spray positive20 on whole board, allow ample time to dry in a dark place, I used to print two copies of the tracks on transparencies using ink-jet, then stick that to the board with the help of few drops water and some cellotape.
I would just use the sun for my UV exposure for the po20, luckily in RSA here, then caustic soda to eat the exposed po20, and then your FE3CL bath.
I used to heat mine using a fish tank heater, and put some bubbles through it using a fish tank air pump as well with a specially modified pipe to make many small bubbles to run across the face of the board.
Yes, I know, tedious process, but I believed it to be cost effective enough to do so. Never knew at the time how toxic the stuff was, just that it stained everything, and ate everything metal.