Very confused and frustrated/sad...

[schmidbauermg]

So everything was going great in my tank as far as I knew. When i woke up this morning my long nosed hawk fish was dead and the hermit crabs were eating it (my favorite fish). I took out the body and checked everything like crazy....and it all seemed fine (results below). I went out for about an hour and a half for a meeting, and came back to find another fish dead (just a damsel, but i still liked it). What the heck is up? After I found that I got super scared. All of my fish are breathing hard and fast it seems, I only have a lawnmower blenny, another damsel, and a true perc left....the emerald and hermit crabs are fine and so are the brittle star and cleaner shrimp as far as i can see. Since the second fish, i siphoned the sand and did a 50% water change, changed the filters, and set it all back up. Only thing i did was add a koralia #2 the other day....
Water test results (before the 50% change):
pH: 7.7ish
Salinity:1.023
NH3/NH4: 0 mg/l
NO2: < 0.3 mg/l
KH:8
CO2:8 mg/l
PLEASE HELP! The fish all seemed healthy........

 

[salt210]

don't know for sure if its your problem but your ph is low.

 

[schmidbauermg]

Can someone.....ANYONE help me?! I'm losing my clown now......

 

[tr1gger]

Your PH is super low, you need to get that up ASAP i would say.. GL man

 

[indigobluetc]

I posted in you other post. Check that out..

 

[beth]

I suggest doing water changes using water that has been well mixed. The pH appears to be too low, and any nitrite is bad. Increase water circulation.

 

[schmidbauermg]

I checked my pH after the water change and it reads at 8.1ish so that is up. Also, I have 2 koralia #2s that have been going, all the fish look a TON better. I was so scared.....it sucks that I lost 2 though....thanks for anyone's help.