API Freshwater Master Test Kit

* Petco.com has API Freshwater Aquarium Master Test Kit on sale for $16.54 when you select "Repeat Delivery & Save". Select Free Store Pickup where stock permits, otherwise shipping is free on orders $35+.
* Amazon.com has API Freshwater Aquarium Master Test Kit on sale for $16.55 when you check out via subscribe & save. Shipping is free with Prime or on orders $25+.
* Chewy.com also has API Freshwater Aquarium Master Test Kit on sale for $16.55 when you select "Auto Ship & Save". Shipping is free on orders $49+, otherwise is Flat-rate $4.99.