Pool chemistry is a numbers game — and numbers you don't track, you can't manage. The right pool app turns a notebook full of scattered readings into a trend line that tells you when something is drifting before it becomes a problem. Here's what to look for in a pool tracking app, and which options are worth your time in 2026.
Before comparing apps, establish what matters. A useful pool tracking app needs to:
Nice-to-have features include maintenance reminders, equipment tracking, and photo logging for documenting equipment condition or water clarity issues.
| App | Price | Chemistry Logging | Dosing Calc | Offline | Best For |
|---|---|---|---|---|---|
| SplashLens | Free | Full | Yes | Yes (PWA) | Pros + DIY homeowners |
| Poolmath (TFP) | Free / $10/yr premium | Full | Yes | Limited | DIY chemistry enthusiasts |
| Pool Pal | Free / $2.99/mo | Basic | Yes | No | Casual homeowners |
| Sutro Smart Monitor | Hardware + $10/mo | Automated sensor | Auto-doses | No | Homeowners wanting automation |
| pHin Smart Monitor | Hardware + app | Sensor-based | Yes | No | Homeowners, automated alerts |
SplashLens (poolens.pages.dev) is a free progressive web app originally built for pool service professionals. It installs directly on your phone's home screen without an app store, works offline, and requires no account or subscription. The chemistry logging covers all standard parameters with trend visualization, and the dosing calculators are calibrated for real-world pool volumes. For homeowners who test manually and want a clean, fast log, it's the most friction-free option available at no cost.
Poolmath is the tool of the Trouble Free Pool (TFP) community — a large DIY pool care forum built around the BBB method (bleach, borax, baking soda). Poolmath's dosing calculators are excellent and calibrated to TFP's chemistry philosophy. The free version covers basic logging and calculation; the premium tier ($10/year) adds unlimited history and additional features. If you follow the TFP method, Poolmath is purpose-built for it.
Sutro and pHin sit in a different category — they're hardware-plus-app systems where a floating sensor tests your water automatically and sends readings to the app. Sutro tests weekly using cartridge reagents ($10/month subscription for cartridges and app). pHin tests continuously with a probe sensor. Both notify you when readings drift out of range. The convenience is real, but the hardware cost ($150–$250 upfront) and ongoing subscription fees add up. For homeowners who forget to test manually, the automated nudge has genuine value.
No app, however sophisticated, replaces professional chemistry knowledge. Apps log and calculate — they don't diagnose. A reading of "high total chlorine with low free chlorine" points toward chloramines, but understanding why that happened and how to address it requires chemical knowledge that an app can reference but not apply. Apps are a memory and tracking tool, not a chemistry tutor.
Similarly, equipment monitoring apps like Pentair ScreenLogic and Hayward OmniLogic control equipment remotely but don't track manual chemistry readings. They're monitoring dashboards for the pool system — not chemistry journals. You still need a separate log for water balance data.
If your pool service professional uses SplashLens, ask them to share your pool's chemistry history with you. Having access to your pool's historical readings — especially if you have a service call or equipment failure — makes it far easier to diagnose what changed and when.
SplashLens is a free offline-first pool chemistry tracker. No account, no subscription — install it on your phone from your browser and start logging today. Built for pool pros; useful for any pool owner.
Open SplashLens Free →Yes. SplashLens (poolens.pages.dev) is a free progressive web app designed for pool professionals and homeowners who want to log chemistry readings, track trends, and reference dosing calculations without a subscription. It works offline and requires no account.
A good pool tracking app should record chlorine (free and total), pH, alkalinity, calcium hardness, CYA, and salt (for salt pools). It should show historical trends, provide dosing calculators, and allow notes for maintenance events. Reminder functionality for weekly testing is a bonus.
No. A pool app helps homeowners track readings between professional visits and catch issues early, but it cannot replace the experience of a trained technician who understands equipment, water balance relationships, and problem diagnosis. Apps are best used as a complement to professional service.
Automation apps like Pentair ScreenLogic and Hayward OmniLogic control equipment (pump speed, heater, lights) but do not typically log or track manual chemistry readings. They may display readings from connected chemical dosing systems like Pentair IntelliChem. For chemistry logging, a dedicated pool chemistry app is still needed.
Test free chlorine and pH at least twice per week during swim season. Test alkalinity, calcium hardness, and CYA monthly. Salt pools should test salt level monthly. If the pool is heavily used, after heavy rain, or if you notice water clarity issues, test immediately regardless of schedule.