So, I've kept fish practically all my life, really got into fishkeeping about 20 years ago when I saved up as a newlywed to get a 46 gallon bowfront tank. I kept a variety of tropical fish (probably a bunch I shouldn't have kept together, but didn't know any better). I was in fish forums and was a familiar face at our local fish store.
Fast forward 20 years and while I've kept the tank running all that time, I fell out of the "hobby" and now I'm back, setting up a 10 gallon planted Betta tank and I'm quickly discovering things have changed a bit in 20 years!
So, tell me (for those that have been around) -- What has changed in 20 years?
I hear undergravel filters are a thing of the past. I've heard some people say not to use carbon in your filters, and numerous other things that weren't being said 'back in the day.'