Okay....you can see below to see the system I have....I know that Nitrates are not toxic to fish, but my nitrates are currently running at 160 ppm
I had a cory cat disappear and I thought he had committed suicide by jumping out of the tank and being eaten by an eager cat or dog, but later found the decaying body inside a rock sculpture in my tank. My ammonia levels were WAY up (they are now getting back to normal, still high but dropping steadily.) and my nitrites were up also, but they are going back down also.
I tested the Nitrates 2x last night and got the same reading each time. I know you want to keep your nitrates below 40, but also hear all the time that they aren't toxic to fish. My question is....even at these levels they aren't toxic????
I also had an algae bloom in the tank due to the decaying cory....can the nitrate level be related to the algae bloom?
Also, anything other than water changes I can be doing to lower the nitrate levels?
Thanks in advance for any help!
edited to include current readings: