Gtreef's 12g Fluval Edge

[gtreef]

My two clownfish died this evening Thinking low O2 did them in, all other parameters were good, Ammonia 0, Nitrite 0, Nitrate 5ppm, temp 78, salinity 1.024... sucks a few shrimp were in distress as well but have survived, I did a 25% water change and didn't fill tank all the way.