Totally worth it! Hobby grade tests are only so accurate, and reagents oxidize and lead to mis information. Great way to keep those test honest. If you dose iodine, potassium, strontium, and any other trace elements. It will help you keep track of what you are doing and if you are dosing too much or not enough. Check heavy metal contamination.... far too many to list. $50 a 1/4 shouldn't scare you too much in this game. $200 bucks a year for a piece of mind is worth it to me.