Clown Fish Aggression?

Hi all. I'm pretty inexperienced with reefing. I received an established tank when I purchased a new house with virtually no instructions on how to care for it.



My water quality has been falling for a bit, but it's mostly high nitrates and phosphates. I'm working on fixing it though. I think it's due to my refugium area in my sump dying off when I first moved in... I'm getting some macro algae and copepods shortly.



Here are the parameters from my testing strip:

- Nitrate: 60 ppm (mg/L)

- Nitrite: 0 ppm (mg/L)

- Alkalinity: 40 ppm (KH)

- Ph: 7.6



My tank is 60 gal had the following inhabitants (these are what I've visually identified them as... I didn't get a list of what they actually are):

- 1 Clown Fish

- 4 Blue Chromis

- 1 Yellow Tang

- 1 Basslet

- 1 Dusky Jawfish

- 1 Marine Betta

- 1 Cleaner shrimp

- A ton of crabs/snails



So here's the problem. I'm missing 2 Blue Chromis. Haven't seen them in days, so I'm pretty positive they're dead. I woke up this morning to see my cleaner shrimp split in half on the sand bed.



I suspect it is the clownfish because I see it snap at other fish often now (it will dart towards them). It also doesn't chill in it's cave in the live rock as much. It does not have a host anemone. I suppose it's possible they're just dying from the water quality, but with the recent aggression, I'm thinking the clownfish is slowly killing off other inhabitants.



I don't have any other equipment (like a spare tank/filtration system), so I'm not really sure what I can do to keep my entire tank from dying :(