Today i went to the LFS to test my 220G water. Turns out my nitrite levels are skyrocketing, everything else is fine, i even did 30-40% water changes every other day to prevent this (tank has been set up about 2 weeks), they sold me a big bottle of "Fritz zyme 7" for 160G of water, and a bag of dirty bacteria water squeezed out from 1 of the shop's sponge filters, and told me to pour both in so i did and not do anymore water changes and let it cycle itself, are they right about not doing anymore changes? i thought changes were suppose to dilute the toxics , i did 30-40% daily, and still high nitrites, will the fish be ok ?