Bare with me on my lack of explanation as my test card(api master testkit) has flown away with the recent winds.

Ok, so i started cycling my tank a while back and my results have been the following

Ammonia= just about 0
Nitrite= super dark purple, between 2 and 5 i think,
Nitrate= super dark red, i think 160

Now get this, I got a sponge and attached it to some pvc to scrub the dark brown alge off my tank, however it was night time and i only tested it by scratching away not even a tad of algae.

I just found out that the sponge wasnt aquarium safe and now here are my results.
Ammonia= a tad green, pretty sure that was .50
Nitrite= light blue, i think that was 0 which is freaking me out how it dropped so much
Nitrate= light orange, which was about 10 to 20, which dropped from 160+

How far back did this set me in terms of cycling?
If i were to buy some of the bacteria from the pet store, is it safe to add with my fish in the tank?
What the hell should i do about that algae now, leave it, or buy an aquarium sponge and scrub it?

EDIT: i went and bought a proper sponge and some stress zyme. no need for panic
Thanks in advance.