Ok, Way beyond my scope of knowledge, but my thought is 15# of FHM is a pretty small amount of money compared to the investment you have in your other fish. So if it were me and I was in doubt................ probably would do it. Only down side is what the FHM cost.
You could skip taking your wife out to a nice dinner and movie next week end and cover that cost. I'm sure she will understand if you explain it to her that is for the benefit of the fish.
