Personally I have always found maintaining proper chemistry helpful in preventing problems. Each person should decide wether the benefits outweigh the gains and I leave that to the individual. If you are going to suppliment the tank chemistry with additives, both
ends of the equation should be monitored or problems will result. If you are not going to test it, don't add it.
If indeed for only FO
, then simple water changes in most cases will correct for most anomalies in chemistry providing the saltmix is up to par. That is if the problem was chemical and not environmental.