5" DSB in the main tank, 4" DSB in the refugium
Nitrates range from 0 - 10 ppm, the upper part of that range started recently due to an overfeeding of phyotplankton. Prior to the phytoplankton overfeedings, nitrates were consistantly 0 - 5 ppm.
I have about 4" in the main tank and about 5" in the fuge, with 0 nitrates. I also have a ball of chaeto in the fuge and C. prolifera all over my main tank, so hard to tell whats really keeping them low.