I would suggest a Protein Skimmer( if you dont have one), it could saves you alot of headaches in near future.
If you are thinking of changing salt I recommend "Crystal Sea Salt" . Its used by Marine Biologist who has mini reefs aquariums. Its kinda like ###### B's Tooth Brush mostly used by dentist
Experience rated: Endorsed and used by hobbyists, retail dealers, public aquaria, universities, and distributors to maintain all types of marine animals.
Dechlorinator added Phosphate and Nitrate FREE!
How big is your tank btw?