CAT exam prep – pool chemistry section is harder than I expected

64% at 7 weeks is workable. I was at 61% and passed with a 77%. The chemistry section is hardest to improve quickly but it's very learnable if you commit to understanding actual mechanisms rather than just memorizing numbers.

Filtration media and backwash procedures also had more depth on my exam than expected. Combined with chemistry that's probably 40-45% of the exam total. Don't neglect that side while you're focused on chemistry.

The Pool & Spa Operator Handbook goes into the chemistry at a level that bridges practical and theoretical well. Read it alongside the NSPF material and the mechanisms start clicking more naturally.

The cyanuric acid section tripped me up too. The relationship between CYA levels and required free chlorine is tested in real detail – you need to know the multiplication factors at different CYA concentrations, not just the general concept.

Honestly felt the same way and almost rage-quit the whole thing around week 4. Four years running pools and I couldn't explain why chlorine behaves the way it does at certain pH levels, just that it does. The theoretical stuff hit different when I had to actually write it out. What helped me was treating the chemistry section like a completely separate subject from my day job, because it kind of is.

Keep pushing through it. I ended up passing and the chemistry section wasn't even my worst score. The stuff I thought would be easy, like cat/questions/hydraulics and plumbing systems, is where I lost more points than I expected. Seven weeks is enough time if you're consistent, and the fact that you already know how it works in practice means the concepts will click eventually, they just take a little longer to stick on paper.

I'm in a similar boat — been working full-time managing two facilities and studying in whatever gaps I can find, mostly early mornings before my shift. The chemistry section caught me off guard too. I thought four years of hands-on experience meant I had it locked, but knowing what to do and being able to explain the why behind it are completely different things. I started blocking out 30 minutes every morning before work and honestly that consistency did more for me than the occasional three-hour weekend cram session.

One thing that helped was treating each subsystem separately instead of trying to study everything at once. I didn't touch chemistry until I felt solid on the mechanical side — stuff like cat/questions/hydraulics and plumbing systems — just to build some momentum first. Once I had a few wins it wasn't so overwhelming. Seven weeks is enough time if you're disciplined about it, even part-time.