Hi there I'm finding it hard to get corals down would this have any thing to do with being a newish tank 3-4 months it's been running but it's does have 4 common clowns, 2 emperor cardinals, 1 tiny regal tang, 1 flame angel and 1 cream angel but do you think the nitrates will drop and yes I have done plenty of water changes and used algone nitrate remover and nitrate minus liquid also have 1 protein skimmer 1 fluvial 405 external filter 1 big internal filter and one little internal filter the tank is 235-250ltrs (uk)