When people start giving advice on how to solve a "problem" when they haven't asked enough questions of the OP to determine if there is an actual problem. For example:
OP: Help! My phosphate is really high.
Person #1: Tell us about your parameters
Person #2 (before OP even answers Person #1's reasonable and material question): You should go out and buy a reactor and fill it with GFO. Or dose Lanthanum Chloride. Or stop feeding your fish altogether!
OP: To Person #2. Thanks! What equipment do you recommend? (OP never answers Person #1's question)
Twenty more messages are exchanged about how to fix the "problem." Nobody ever gets the relevant information.
Turns out OP is a newbie that knows almost nothing and the phosphate levels are fine.
caveat is when you start asking too many questions, they don’t answer all of them.