Have a 75 gallon display with 40 gallon sump with refugium in sump. A couple of weeks ago, I began detecting ammonia (.2), Nitrite (.2) and nitrate (50). The tank has been running for 6 months and has been stable. All of a sudden, this issue began. Any recommendations? My nitrates don’t seem to be dropping. I have been using prime to detoxify for now, but I know that is not a permanent solution. I have been doing about 15% water changes, daily.