I haven't used that particular product, but my thoughts are (and remember, you asked for it):
If it ain't broke, why fix it?

Your fish are spawning so that seems to indicate that things are in good order, congrats!
It's when we mess around with the water chemistry things tend to get unstable/dangerous for our fish and a worry/hassle for us.
Keeping your water clean with regular filter maintenance, routine substrate vacs and partial water changes is inexpensive and the best use of our time and money.
I'm not against spending money on this hobby, Lord knows it takes alot of $$...
It's a good idea to occasionally check your replacement water, as well as tank water, for fluctuations.
So, having test kits for
pH,
GH, and KH (that aren't too old) to do that is a good expense.
A good dechlorinator like Prime is money well spent.
Purchasing quality foods (& replacing them every 2 months), saving for better filters, new fangled heaters and more fishies

is where I want my hard earned cash to go.
Not on chemical additives when things are already balanced.

my 2 cents,
alicem