Okay, you're an experienced hobbyist...you've been around the block, experienced algae problems, ich outbreaks, cloudy water- everything...You've been on a sort of "cruise control" in recent years, right? I mean, you're learning new stuff, pushing yourself...You don't make many mistakes these days, or so it seems.
Then one day, something goes wrong. Like, you can't figure out what happened... and your ego might be a little bruised.
You get totally frustrated, because this kind of stuff shouldn't be happening to YOU, right?
I've been there before, and you know what? The "anomalous problem" is almost always traceable to some lapse in my judgement- or a decision I made based on thinking "I've got this covered..."
In other words, when i get complacent, I screw stuff up. Or, when I let foolish pride get in the way of my better judgement. I mean, there is a REASON why things were going so well up to that point...It's because what I was doing really worked.
And once you start tempting fate- thinking you have the upper hand- or you can "squeak by this one time..."- that's when stuff goes South.
S0, my quick and dirty advise to you- If it's working- keep doing what you're doing. Period.
Easiest advice I've ever given- and the most certain rule for success I've ever followed.
So, when stuff goes wrong out of the blue, trace the problem out, and correct it by doing what you were doing before!
Sure, this isn't ALWAYS the only reason or solution, for example, if a heater sticks in the "on" position, your water company starts tripling the dose of chloramines in the water, or you get a batch of contaminated food- stuff like that. But many times, sudden problems in an otherwise perfect fish keeping experience almost always seem to have a "human" origin...
Never get too complacent in fish-keeping.
You've got this.
Just something to think about, right?
Have a good day..Stay the course...
And Stay Wet!