Oh I didnt forget, I did boil in half the water for 5 mins (more actually) at a very low flame.
By the way, the pH came out to around 6ish without adding any acid.
Also, I found out that you usually add 15 grams of agar per 1000mL of anything to make it solid. So I really think 5 grams is not enough.
In anycase, all the burnt stuff stayed stuck to the bottom of the pot and then the glass beaker(when I redid it). SO hopefully it will all be ok