With nitrites of 2ppm I would do daily 50% water change and add a double dose of prime to help detoxify any ammonia or nitrite till it constantly stays at zero the ram on the in the middle of the picture looks like it's go a sunken if so you would need to treat with levamisole once a week for for for weeks am not sure if that's cyanobacteria it could be an not the best when it comes to Identifying algae @Lennie