It sounds like you need a lot more bacteria to take care of nitrite, on the top of a little bit more bacteria for ammonia.
I do not believe it is algae. It could be debris from rotting plants.
The leftover live bacteria in an opened bottle won't do you much good if you do not use it up quickly. Once the unsealed, it will degrade rather fast.
I know the waiting is painful. Consider you are already using live bacteria product, it will take you way less time than those people who do not have such luxury. Without the heavy seeding from live bacteria, it could take a month and half or even longer.
I am gladly to do my best to answer your questions.
