nitrate issue

I have a waterbox reef lx290.6 Roughly 288G tank/sump. I currently have high nitrate due to poor maintenance. Was on vacation then been sick for about a month now. I wasn't able to do water changes. I plan to do a large water change this weekend. The amount of water I need to replace to...

I've been trying to lowering my nitrate level with frequents water change and decreased feeding on my 15 gallon nano but it barely have any affect on them, the phosphates was normal at 0.03 ppm but the nitrate was at 50 ppm. I haven't got an algae problem yet, but few corals are closed...

So i have had this 60litrs nano tank for about 6months now. I have two birds nest coral frag, one funghia, few zoas, ome chalice and one hammer. Fishes only 3. Initially my params were:- Dkh-8-9 Calcium-420 Nitrate- 0 (negligible) Salinity - 30ppm All corals were growing healthy and hammer...