Keep up with the water changes anyway, but i would question whether your nitrites are really 7. Strips are inaccurate at best. If you can invest in an API freshwater master test kit, it will be well worth it! Amazon sells them for about $10 cheaper than most
lfs. The cost over the long haul winds up being pennies a test because there are over 800 tests in a kit. It will give you an exact idea of what your tanks parameters are truly reading.