You would be surprised how much salts can build up especially with a hard water source.
Water with distilled water or water from an RO system.
Fertilize a lot less than recommended...I do about once every 4 weeks and only during active growth.
If you really want to "see" how much salt you are building up, plant one of your specimens in a clay pot and the salt residue will build up along the outside...EWW
High salts are hard on the root systems and will cause necrosis of the roots making them susceptible to bacterial and fungal infection and causing the ultimate death of your plant