Tank is 4-1/2 months old. 180 gallon system with 6 fish - 2 tangs (yellow and Kole), 2 clowns, lawnmower blenny, and a melanaurus wrasse. Fish look great. Coraline algae is growing well on the dry rock in the tank. But.....added some zoas and euphyllia in the tank and none are thriving. Color is good, but no extension on the euphyllia. Zoas are a mixed bag. Two are doing well, two are doing okay, and two just look ticked off (closed tubes). Lighting is six t5s (three blues, 2 coral plus, 1 actinic). At first I thought the corals were getting too much light, so I scaled that back to just 8 hours a day and moved all corals to sand bed. No change in coral health. Scaled flow down to low flow (less than 40% from two 2k ice cap gyres on either end of the 6 foot tank. Additional 1200 gph spread to four returns (from sump) at surface of tank). No change in coral health observed after two weeks.
After more research, the advice was phosphate needed to be increased. Red sea has been testing at 0 consistently for entirety of tank life. Other parameters staying pretty consistent:
Alk 8.5
Calc 420
Mag 1400
Nitrate 4-8 ppm
Salinity 1.0255
pH 8.2
Stopped skimming a week ago, began adding phytoplankton daily, removed filter socks, feeding benepets reef food 3x per week. A reddish purple web has started covering the sand in places (see picture) in the last 3-5 days and is getting stronger. My thought was that this was probably due to my low nutrients and consistent with my thoughts about the phosphates.
My Hanna checker arrived yesterday and tested phosphate at .05 and .07 thirty minutes apart. Confusing results based on what I expected was going on in the tank. Red sea test kit still tested phosphate at 0. Not sure which result to believe. I was planning to start dosing phosphate, but now I'm not sure if that is the best course of action. The plan was to shoot for phosphate in the .03-.05 range while keeping nitrate in the 5-10 range. Decided to wait a day and test before adding anything to the tank in the morning.
Before adding phyto, Hanna tests at .04 and Red Sea still shows 0. Getting ready to vacuum my sand bed and do a water change, but not sure how to proceed after that. The coral health and the sand bed still say low nutrients, but the Hanna test has me doubting that conclusion.
Would you add phosphate, and, if so, which test kit would you believe? I feel confident I am using the test kits correctly, but the varying results are confounding. What would your next move be? Thanks for any other insights you might have.
After more research, the advice was phosphate needed to be increased. Red sea has been testing at 0 consistently for entirety of tank life. Other parameters staying pretty consistent:
Alk 8.5
Calc 420
Mag 1400
Nitrate 4-8 ppm
Salinity 1.0255
pH 8.2
Stopped skimming a week ago, began adding phytoplankton daily, removed filter socks, feeding benepets reef food 3x per week. A reddish purple web has started covering the sand in places (see picture) in the last 3-5 days and is getting stronger. My thought was that this was probably due to my low nutrients and consistent with my thoughts about the phosphates.
My Hanna checker arrived yesterday and tested phosphate at .05 and .07 thirty minutes apart. Confusing results based on what I expected was going on in the tank. Red sea test kit still tested phosphate at 0. Not sure which result to believe. I was planning to start dosing phosphate, but now I'm not sure if that is the best course of action. The plan was to shoot for phosphate in the .03-.05 range while keeping nitrate in the 5-10 range. Decided to wait a day and test before adding anything to the tank in the morning.
Before adding phyto, Hanna tests at .04 and Red Sea still shows 0. Getting ready to vacuum my sand bed and do a water change, but not sure how to proceed after that. The coral health and the sand bed still say low nutrients, but the Hanna test has me doubting that conclusion.
Would you add phosphate, and, if so, which test kit would you believe? I feel confident I am using the test kits correctly, but the varying results are confounding. What would your next move be? Thanks for any other insights you might have.