Challenges with lps corals

[barkwood]

I'm still pretty new to the saltwater scene, having just taken over a pet store with a small aquatics section back in September. Since I've got a background in mammals, I figured the best way to learn about SW was to set up a tank at home and do my research so I could better advise customers - thankfully, the store came with a fish expert, but even he's stumped on some of this stuff.

I started my 29 Biocube in November with R/O salt, live rock, and live sand. The lighting's still stock, but I've added an intank media holder with ChemiPure, Purigen, and floss. I've also got the intank fuge set up with chaeto and copepods, along with the Biocube UV Sterilizer and Protein Skimmer - I know the skimmer's not the best, but I didn't want to mod the tank just yet. The Biocube circulation pump is pointed almost perpendicular to the stock flow.

I've lost most of the LPS corals I've introduced, except for a Fox Coral that's been doing fine. My mushrooms and a few Zoas were doing well initially, but the others have started struggling over the past few weeks. I'm worried they might be on their way out too. On a separate note, I had a flame angel that was thriving for four months, but it suddenly died on me - I tested the water and couldn't find any issues. I also lost an orange tree sponge.

Here are my current parameters:
Temp: 78F
S.G.: 1.024
pH: 8.2
Ammonia: 0ppm
Nitrites: 0ppm
Nitrates: 0ppm
Phosphates: 0ppm
KH: 160ppm
Calcium: 480ppm

My tank's got a B/W Oscellaris, a Purple Pseudochromis, two Mandarin Gobies, and a cleanup crew consisting of Turbo Snails, nassarius snails, peppermint shrimp, a fireshrimp, and a Brittle Star.

I'm using a mix of supplements, including Kent Coral-Vite, Purple Tech, Iodide, Strontium, Molybdenum, and Calcium. I target feed 3-4 times a week with Reef Energy A/B and a Phytoplankton Mix.

I'd really appreciate any help or advice you guys can offer - go easy on me, I'm still learning!

[rustyfox9]

I've heard flame angels can be a bit iffy in reef tanks, some of them develop a taste for corals, especially LPS. Might be worth considering that as a possible source of your issues.

[barkwood]

I hadn't noticed the flame angel bothering my LPS corals, but now that he's gone, I'm curious to see if there's any change in their behavior.

[kingrise]

I'm curious, have you checked your Magnesium levels recently, as it's an important parameter that can impact the health of your corals, especially LPS, and might be a contributing factor to the issues you're experiencing.