yikes heavy nitrates reeked havic in my reef

[Snappy]

Between my 3 tanks and the sump I have 240 gallons of water capacity, I did water changes of 10% x4 in the last 5 days which equals roughly 80+ gallons so hopefully with my new skimmer and these multiple water changes my system can now cope with the nitrate problems caused by my previous skimmer failing. Any ideas? Should I do more water changes this week as well? I lost a few pieces to RTN and a lot of corals are either bleached or browned out. Damn nitrates I would hope my system can handle the load now but am looking for some input.