PCB etching

Today, i etched my first PCB. I used Toner Transfer Method, for it i used a simple one-sided copper board and a laser printer to print my circuit on a photo paper sheet, which later i ironed to the board. The traces weren't perfect, but for my first PCB they were good enough (i used a anti-etching marker to fix the traces). After taking of the photo paper it was time to start etching it, for this i used ammonium persulphate, in my opinion it is better than ferric chloride, because:
     1. It is much less agresive, so if you spil some of it, it wouldn't be a problem.
     2. It is transparent so you will by able to observe your board while it etches.
     3. Its by-product is O2 (oxygen) so there is no need to keep your room ventilating.

Since i don't yet have a special container for etching, i used a simple plastic box in which i could fit the board, tried to keep it warm and from time to time shaked the board. Here is the result :)

Circuit diagram (didn't found the one i printed, the diffrence is that a filled the circles):

Still etching:

After etching:

How to do it, step by step:
1. Make a circuit diagriam using any program of your choice (i used "Eagle", but there are many more)
2. Print it on  a sheet of photo-paper with a laser printer (otherwise you can damage the printer).
3. Then take your board clean it and scrub it with steel woll.
4. Put a thin towel on your board and heat it up with an iron.
5. Put the printed sheet (printed side face down), and iron it to the board, use the tip of the iron to make sure all the traces would stick to the board (15-20min.)
6. Place it in a container full of hot water (wait until the traces become wisable) (30-40min.) or even longer if needed.
7. Take out and peel of the paper, first use your hands, later if there is some left use a toothbrush, but don't scrub to hard, you may damage the circuit.
8. Then make your solution, i mix ~250grams to 1liter of warm water, but it's best to just pour until it doesn't dissolve anymore.
9. Put the board in the solution and wait (30min.) if you can keep the solution on ~30-40C temperature , if not, it may take longer, don't forget to move the board time by time, it helps to etch.