A big update: a free mock exam, ten new calculations, and a rebuilt CT tool. TRY IT BEFORE YOU BUY Take a free 10-question scored mock exam, once a day. Same engine as the full test — flag questions, skip and come back, change your answers — and the same full answer review afterward. You see where you stand before deciding on anything. REVIEW EVERY ANSWER After you submit, walk back through the whole exam: what you picked, the correct answer, the explanation, and the standard it comes from. Flagged questions are marked so you can find them fast. CT DISINFECTION, REBUILT The tool now works on T10, not theoretical detention time — enter your detention time and pick your basin's baffling condition, and it converts for you. Target log inactivation is selectable and defaults to 3-log. Required CT comes from a lookup table instead of a rough formula. TEN NEW CALCULATIONS Pump & Hydraulics — water, brake and motor horsepower, wire-to-water efficiency, total dynamic head, psi to feet of head, well specific capacity. Filter & Basin Loading — filtration rate, backwash rate, backwash water as a percentage of production, surface loading rate, weir overflow rate. Water Chemistry — dose equals demand plus residual, two-source blending, percent removal, fluoride feed corrected for purity and available fluoride ion, and the Langelier Saturation Index with a scaling or corrosive reading. Every calculator shows the formula it used, so you can check the work. STUDY GUIDES Five topic guides and six flashcard decks, with spaced repetition that brings a card back right before you'd forget it. Learn, memorize, practice, test. BOOKMARKS Tap the bookmark on any question while practicing, then find them all in Settings. MORE HONEST ABOUT WHAT'S HERE States with questions written for their specific rules are marked with a star — California, Texas, New York and Florida. Every state gets the full federal and general operator bank: EPA rules, treatment, distribution, math and lab. ALSO IN THIS UPDATE An annual plan alongside monthly and lifetime. Daily study reminders. VoiceOver labels on calculator results and study cards. Layout that scales properly at large text sizes. A faster launch, and a fix for a rare startup failure.