Your nitrite level is in the caution/stress zone. I would continue to test and do water changes. As for the aglae it is due to nitrates. To reduce nitrates, you could make a 25% water chande and add bacteria/enzyme product (such as Start Zyme) or nitrate ion exchange resin. Also a 25% water change will help reduce nitrite and adding aquarium salt or nitrite ion (like you had done). Ammonia may also be present and you could add an ammonia remover (such as Ace). Jungle makes great products. I have always been very happy with them and Wal-mart even carries Jungle products. Good luck and hope I helped.