Help with Reef Tank please

Hello!



I have been attempting a reef tank for about six months now and it has been a very rocky transition from a freshwater cichlid tank to this beast.. The specifics of my tank are posted below.



My issue is with keeping my coral happy. They seem to do well for a couple weeks when introduced then they seem to not open fully or not all. I am currently keeping a frogspawn coral (which initially grew a new 'head') then just sputtered. I also have an ACON which is not opening and a candy cane coral which is slowly opening less and less.



I also have a zooanthid which seems pretty happy.



Any tips would be appreciated.



Thanks in advance





Tank Hardware Details

• 90 Gallon Display Tank (DT)

• 40 Gallon Breeder Sump / Refugium (divided into 3 -- i) drain area; ii) refugium; and iii) return area)

• 1500 gallon / hour overflow box

• 2 x 300 Watt heaters – One in DT, one in sump (return area)

• 4 x 900 gallon / hour powerheads in DT (2 banks of 2, set on timers which 'randomly’ alternate on/off status)

• 1 x 200 gallon / hour powerhead in sump (drain area)

• 1 x 1300 gallon / hour Return pump in sump (return area)

• Protein Skimmer – reef octopus 110 INT in sump (drain area)

• Carbon in sump (replaced every 1.5 ish months)

• Course filter media (sponge) on a shelf in the sump, under the drains to buffer noise from drains (changed every three days)

• T5 lighting 4 x 54watt ( 2x antics on at 11 am off at 10 pm, all lights on noon till 9 pm, moonlight LEDSs on all night)

• Digital temperature meter with thermometer located 4” below water surface



Tank Parameter Details

• All water used in tank purified using RO/DI unit

• All water (water change or top off) is treated with API Proper pH 8.2 as directed

• Salt added for water change is Instant Ocean brand

Current (3/22/15) water parameters prior to the weekly 5 gallon water change are:

• Alkalinity = 11 dKH

• Ammonia = 0 mg/L

• Calcium = 480 mg/L

• Nitrite = 0 mg/L

• Nitrate = 5 – 10 mg/L

• pH = 8.2

• Phosphate = 0 mg/L

• Salinity = 35 ppt

• Temperature = 75.5 to 76.4 Celsius







Tank Inhabitant Details

• Healthy Chaetomorpia in Refugium

• Small dying off population of green hair algae in display tank

• Cynobacteria in Refugium

• Coraline algae establishing on live rock and ‘filler’ rock (mostly lime green and red stuff)

• 2 Healthy Clown Fish

• 5 blue legged crab

• 2 Welk snails

• Large population of arthropods

• Roughly 1.5” sand bed in DT (aragonite)

• Roughly 7” deep sand bed (aragonite) in refugium with presumably, the associated bacteria