Conversion from ULNS to LNS SPS Tank

Greg Vontz · 04/04/2020, 05:49 PM

For the past few years I have run a 150 g mixed SPS/LPS tank as an ULNS with no detectable nitrate and phosphates at less than 0.05 ppm. The ULNS was with vinegar dosing. Realizing that current thoughts on coral nutrition and coloration are geared to nitrates in the 10 ppm range and phosphates in the 0.08 or lower range I decided to move away from the ULNS. Over the past month and half I have slowly raised my nitrates to roughly 8 ppm via KNO3 dosing and continued to manage phosphates at 0.05 or slightly lower. My SPS are looking better but my tank has now developed a red-brown algae on the shallow sand bed. Its not cyanobacter. I do Triton ICP and N-Doc testing. Silicates are very low. I knew any transition from a stable situation would cause some disturbance. Has anyone else made this transition and seen similar problems? Would welcome any advice or thoughts.

04/04/2020, 05:49 PM	#1
Greg Vontz Registered Member Join Date: Jan 2004 Location: menlo park, CA Posts: 14	Conversion from ULNS to LNS SPS Tank For the past few years I have run a 150 g mixed SPS/LPS tank as an ULNS with no detectable nitrate and phosphates at less than 0.05 ppm. The ULNS was with vinegar dosing. Realizing that current thoughts on coral nutrition and coloration are geared to nitrates in the 10 ppm range and phosphates in the 0.08 or lower range I decided to move away from the ULNS. Over the past month and half I have slowly raised my nitrates to roughly 8 ppm via KNO3 dosing and continued to manage phosphates at 0.05 or slightly lower. My SPS are looking better but my tank has now developed a red-brown algae on the shallow sand bed. Its not cyanobacter. I do Triton ICP and N-Doc testing. Silicates are very low. I knew any transition from a stable situation would cause some disturbance. Has anyone else made this transition and seen similar problems? Would welcome any advice or thoughts.