50% water change and still 20ppm nitrates

[ottoman]

[quote=naesco;549350]Milan I understand your tank is running for less than 5 month.
With respect, you need to have patience.

++1.....if your tank is only 5 month, I think it is not fully cycled yet. Fish may be okay, but not even hardy corals. I remebered I lost a few corals when I first started saltwater years ago. Be patience. Check your flows, keep skimmer running 24/7, it helps cycling.