There is science behind this statement though.
But the scientific back-up to defend a "turn your lights off earlier" isn't necessary.
"Why?" you ask. Because in my experience and that of multiple individuals, reducing the amount of light solves the issue.
There is not need to prove the photosynthesis period of suspended algae to make the suggestion.
It is a scientific fact that plants such as algae require light to photosynthesize.
As it is also a fact that many people have experienced that suspended algae is often a cause of excess nutrients and too long of a photo period. Thus the "turn off your lights and do more water changes" response is valid regardless if it is backed up or not.
Making wild claims like VitC increases Collagen/Cell Wall Thickness in a marine organism or claiming that you eliminated a parasite which has been proven by science can not be cured using VitC is misleading and unfortunately false as well.
I am pretty sure that the individual said that is what works for them.
As far as sourcing things. Source the bolded above.
Saying VitC cured Crypt is similar to saying a human taking a multivitimin every morning prevented them from getting a tick while camping. It is simply incorrect
We don't live in a black and white world tooth. Every tank is different. Every species is different.
I used to eat matches, the kind that make fire, before going to the field in the army. The thought was that the sulfur in the match head would sweat back out of you in low dosages and keep the bugs off of you. Did we have scientific proof to back it up? No. Did it work in my opinion? Yes. Would I recommend it to somebody else in a similar situation?
Sure.
The point is. This is a discussion forum. This isn't a peer reviewed, scientific, know-it-all conference.
If you can prove that somebody was inaccurate in their claims, or if you want somebody to back up a fact they presented... thats one thing. If you are saying people can't make suggestions on anecdotal information they have from experience, then I think you are wrong.