Purple Coraline Dying off

Hi, I have a saltwater aquarium that was doing great, but I recently moved and been having some issues since. I had a lot of puprles/red coraline algae, but notice it has been dying off recently. Went to LFS and they recommeded I check water parameters (which I did, I know out of whack) but also suggested I try "Reef Fusion 1/2". It's a two part system to boost/maintain the calcium/alkalinity. I checked the levels and see the phosphates and nitrates are very high so going to do some water changes.

My question though, would this cause the coraline algae to die off? Noticing more green/brown now. Also, it looks like my calcium/alkalinity is already a good level, so would it hurt to start using this additive? Lastly, they also suggested I try adding Trace Elements. Before I add any of this, want to see what I should/shouldn't be adding as I don't want to make it worse.

Before I moved, the levels were much better as far as nitrates, but my engineer gobies are much more active here and often stirring up the sand, not sure if this is good or bad? They were much calmer before the move so wouldn't stir things up nearly as much.


-90 gallon
-about 70 lbs live rock
-Protein skimmer in sump
-Phosphate reactor in sump
-1 Sailfin tang about 8 inches
-1 blue tang about 7 inches
-3 engineer gobies (about 9 inches each)
-2 small clowns
-several mushroom corals
-PH is about 8
-nitrates around 160
-phosphates around 5
-Calcium 460
-kh/alkalinity at 214 ppm/4.273 meq/L