High Nitrates in new aquarium


Reefing newb
Hi all,

It's been over 2 weeks since i upgraded to a 330L from 250L aquarium and after several 50% water changes (3 a week) i cannot lower the Nitrate levels from 80ppm. I did lower it to 40ppm but it quickly rose back up again within 2-3 days. The Ammonia and Nitrite levels are 0. PH 7. I have been using the API Freshwater Master Test Kit. I have also tested my tap water for nitrates using the same test kit and the results were 0.

Bit of background about the upgrade. I am using the same filter from the 250L tank (All Pond Solutions 1400EF External Aquarium Filter) with the same media that was being used before. The media was rinsed in tank water during the change over. I use 3 sponges for the mechanical filtration and biohome ultimate for the biological filtration. No carbon. I transferred between 180L to 200L of water from the 250L tank to the new tank.

The new 330L has new substrate (CaribSea Eco Complete) 3/4 the length of the tank and new sand substrate in the other 1/4. The tank is well planted with new plants (not replanted from old tank). I also have 2 airstones installed, 1 to the left of the tank and one in the middle. The trickle bar from the filter is positioned to the right.

Any advise on how to lower and keep low the nitrates would be much appreciated.