High nitrates after tank upgrade - please help

Dave Reef · May 5, 2023

Hi, I recently moved my fish and rock and coral from an established (3 year old) 20-gallon tank to a 70 gallon display + 20 gallon sump. I did not move my sand. I had a fair amount of livestock and coral for a 20g but for my new tank it looks pretty sparse. I put in Carabsea Arag-alive sand and I put in a bunch of new dry rock in my display and sump. In my small tank I had been dosing NOPOX to keep my nitrates and phosphates low (1 and 0.03) respectively. New tank has been up and running 3 weeks. I am not dosing anything. Phosphates = 0.06 and nitrates = 16. Nitrates too high? Too early to dose anything? KH =8 and Calc = 400. I am doing a 1 gallon per day water change. I have a big Octo skimmer and I have an algae reactor that has not sprouted any algae yet. I have filter socks that I change 2x per week.

lopez052308 · May 5, 2023

Why did you keep nitrates so low in the last tank? Nitrates at 15ppm is what I usually aim for. I don’t see to much of a problem. Where your corals thriving with 1ppm nitrate in the 20 gallon?

Dave Reef · May 5, 2023

Yes my tank was full of corals. Algae also liked to grow, which was why I kept nutrients low.

cwerner · May 5, 2023

New dry rock, if it wasn't properly cured, can emit lots of stuff into the water, including nitrates/phosphates. It's not too early to start carbon dosing if that's what you were doing in the previous tank. That or BioPellets would probably do a good job of reducing nutrients. It could also be that your algae reactor is undersized, but I have no clue. I primarily use Algae Scrubbers for nutrient export now.