ICP test

[lost66]

I am about to send a water sample for ICP test. I dose seachem amd DIY amino acids, I change water once a week. When would be the best time to take water sample? Before/after water change, something in the middle? Before dosing or after? Or something in the middle?

 

[Miami Reef]

Perhaps before the water change/dosing, so you can see if any elements are accumulating or depleting that would otherwise seem fine after a water change.

Taking an ICP sample after a water change is like taking a Tylenol before going to a doctor for pain.