SPS slowly dieing off

I purchased these pieces about one or two months ago and they all have been growing. When school started, I neglected the tank a bit but now I'm slowly coming back. All the other LPS and softies are doing fine, except that my SPS are starting to lose its tissue and color.
I started doing 5 gallon water changes every other week starting a month ago. I feed the fish and corals only once every 2-3 days.
I dose 20ml of ESV B-Ionic two part calcium and alkalinity solution everyday. Here are the tank specs
40g
45g sump/wet&dry
90lbs of LR
45lbs of LS

pH - 8.2-8.3
nitrate - 0-5
ammonia - 0
nitrite - 0
calcium - 400

Im still working on raising the calcium up to 450 and lowering the nitrates. Here are the pictures of the corals.






What can I do to ensure that they will be able to come back and regain its color and tissue? Could it be possible that the algae;cyano I believe; is taking the nutrients in the water so there is none for the corals?

BTW I had an outbreak of dinoflagellates about 3 months ago which I had under control, but now this is showing up.




I've already cut down on the lighting schedule from 9 hours of actinic + MH to 5 hours of only MH, cut down feeding, and increased flow. Could it be possible that the plastic from of sump is causing problems in the water? I will be changing the tubbaware to a 40 AGA as my sump/wet&dry.

Thanks for your time

 

lights with depth of tank? PO4? dKH? Mg? Sr? Si? internal flow? refugium?

 

Whats your temperature and salinity?

 

The corals are about a foot under a 250w MH I believe its 14K.
I have never tested for any of those that you listed. I have a pump rated at 1000 GPH that shoots up through a 4 feet return line into a spray bar that is controlled with a ball valve. I also have an AC 402 and an AC 30. My sump/wet&dry just holds filter floss, a thin layer of bioballs, about 30lbs of LR, a skimmer and the pump.
Temperatues are 73 in the night at 75-76 during the day. Salinity is at 1.024

 

One thing that may help is running actinics, that ware length helps corals grow. By not running any actinic that may be contributing to the problem. Just an idea

 

what brand name 14k? pc's?

with acro thats not a wise choice

to low at night, try a heater for a constant 77 which is safe, some recommend higher, chiller?

to low, 1.025 will work, 1.026 is better

 

yea what he said, lol.

 

Do you run Carbon? Softies release a toxin in the water that kills stony. I've also been told a low kh is an sps killer - but you dont test for that.

TBH, as far as i am aware SPS are amongst the most challenging to keep and should be done in species only tanks and require absoloute pristine water qualities. They should be handled by the uptmost experienced aquariust who has the time to make sure the aquarium has spot on parameters.

 

as long as calcium is at 400 i think you are ok. I would work on all of the other stuff first like temperature (76-78), lighting, salinity (1.025-1.026), dkH (10-12). Also phosphates are pretty important when it comes to sps. You need to lower these asap if they are high.