Hi, I set up a new 19l tank 3 weeks ago. I let the tank run for three days and then stupidly added safestart ('live bacteria') and 3 harlequin rasboras, after being told it would be fine. The fish died overnight so I took them out. Since they died I left the tank running and done a lot of research of cycling. I tested the water, which was 1.5 ppm from the fish. I left it for two weeks at about 2ppm and then decided to turn the temp up to 32 degrees and added 0.5 ml of 9.5% ammonia. It has been three days since adding the ammonia which is at 6-7 ppm (was aiming for 5ppm) and no nitrites. Can someone help me out and reccomend what to do. Do I need to do a water change? Also, a lfs sell mature filter media at 1p each (ceramic rings) but I have a sponge filter, could I attach them to the outside of the filter and the bacteria would transfer? Thank you. p.s there is also a bit of algae building up around the filter and gravel, also can I add plants now some places say wait and some say it's ok?