Hello, newbie here. I started my reef tank 2 years ago but really still consider myself a newbie. I have a 300 liter tank with live rock and live sand, a few soft corals and 7 fish, clowns, damsels, a blue tang, a pyjama fish and very recently a mandarin. Over the summer, I must say I neglected regular water changes and although I resumed my routine in October, I have always confused NO2 and NO3 and never tested for NO3...anyway, on the day I bought the mandarin, I took some tank water to the shop to be tested...all was well except nitrates that were wayyyyy out of limits 120!!!!!!!!!!!! So.....doing what the salesperson told me, I put some anti nitrate in the skimmer's media chamber and did an emergency 50% water change, and three 30% changes over the last 5 days,bringing the nitrates down to 50. But 50 is still very high isn't it? What do you think I should do? More water changes? I have already eaten through a huge box of reef salt in the last week. Or let the anti-nitrate do its work with maybe a large water change in the next week? How dangerous is this for fish and corals? The fish seem absolutely fine, the corals have not been opening for a while, but are now starting to. Really grateful for any input. Oh....I don't use any mechanical filtration, no sump either, just a Deltec MCE 600 skimmer with carbon and antiphosphate (which I have now taken out to put the anti-nitrate in) and the live rock and sand. Sorry for the long post but I could really do with some expert help. Thanks!