This is what I've learned as of late from MFK.....
All Potomotrygon species are just "rays". The names given to them are nothing more then made up crap that drives the price up, some of the names are from other animals, and some were 80s bands, all the names are jokes.
UV lights are all the same. Why spend good money on lights that are overpriced? UVs don't need R&D'd and paying someone to design them is a waste of money. You don't get what you pay for you get ripped off if you're not buying them off Ebay.
All filters are the same. You don't need anything fancy at all. Socks like fluidized beds are rubbish and a waste of time and money. All you need is a pile of Jap mat and a sand filter. Rinse your Jap mat in tap water once a year and "you're golden ponyboy."
I'll tell you what's rubbish, trying to enjoy the hobby on this site these days.
And people wonder why it's so hard to get decent info these days...... Anymore it's nothing more then a game of who can contradict who faster in a public display leaving the people actually wanting to learn so dang confused they don't even want rays anymore. And I hope the people "giving advice" are achieving some sort of satisfaction by providing "technically correct" answers that are only right to them in thier situation with variables that are a mystery to the rest of us.