Without tests, it's hard to say (hence the reason we advise people to have their own--it's easier than always running to the LFS). The key is to get ammonia and nitrites down through water changes. I would start doing a 20% water change daily, and then adapting that based on the test results, to keep ammonia <1 and nitrites <.25. Adding a small amount of salt (NaCl) will reduce the toxicity of nitrites--1 tsp/gallon of regular table salt will work (and watch for the outcry against iodine--it's a myth that table salt will kill your fish).