Imo, if you have to go to youtube for your fish advice, you are going to become an expert in dead fish. The way to know who not to follow is, the more subscribers they have, the more they should likely be avoided.
I am a privacy nut so I do not use social media. I do view things on youtube, mostly live concerts somebody has filmed. I work with a partner to sell the fish I breed. He has a Facebook site. I used to visit to see the minimal things Facebook allowed non-memeber to see. About a week or so back i went to look and was greeted by an announcement I must log on to see. So now I do not have to waste any time at all on Facebook.
For those of you who follow these sort of Youtube sites and are registered with Google (I am not) here is a way to have some fun. When they do stuff related to cycling, post a this question. "I am curious where you stand on the ammonia oxidizing bacteria vs, the ammonia oxidizing archaea in aquariums. What role do each play?" You might also ask their thinking on complete nitrification being done by Nitrospira. Maybe even ask them the best way to deal with nitrite in a tank with fish. (The answer is chloride.)
The primary function of Twitter is to empower idiots.