Isn't this a new system? Just stick to your weekly 10% water changes and throw the API test kit in the trash. You won't need to test your alk
, calc, or mag levels really. The weekly water changes will replenish the elements utilized by the corals in a system with the exception of some very heavily stocked SPS
systems. If you get to that point and level, you'll have already invested in accurate test kits for them like red sea or hanna checkers.