I have a 30 gallon freshwater tank, nothing fancy as I wanted low maintenance because it's in my shop. It has blasting rock for substrate, rocks, some live plants, and then for fish it's got cory's, testras, and some algae eaters (about 12 fish); it's pretty basic. It has been up and running for ~ a year and a half and has had the same fish since the beginning. Other than the routine cleaning, filter changes, water swaps, and minor stuff, nothing has changed, and especially nothing in the last few weeks. I went out yesterday and found one of my cory's dead. I was bummed because it's the first fish I've lost on this tank, but I didn't think too much of it since the tank itself hasn't showed any signs of anything going wrong. The rest of the fish are all very active and nothing appears to be off, so I figured it was just this fish' time. Well I went out today and I found another one of my cory's dead...that's 2 cory's in 2 days. Now that starts to make me think something might be going on. I grabbed my PH tester and checked it and it came back at 8.25. I believe that's a little high, but is that high enough to start killing off my fish? I haven't had any problems prior to this so I haven't tested it consistently, so I don't know what it normally is. Looking for direction on where to go. Should I try and start lowering my PH? Or do you think this is just a coincidence? Any direction or advice is appreciated, thank you.