Simple pricing
All calculators free. Plus is coming.
Everything on this site works without an account. Plus is for keeping several tanks in sync across devices and getting a history of what you dosed and tested.
Available now
Free
$0
- Every calculator: EI, lean EI, PPS-Pro, low-tech, custom
- Dry dose and stock solution modes
- Product library and mixed plans
- Saved tanks in this browser
- .ics calendar reminders and printable chart
Coming soon
Plus
$2/month
or $15/year
- Unlimited tanks, synced across devices
- Email or push dosing reminders
- Dosing log: tick off each dose
- Test-result tracking with charts (NO₃, PO₄, GH, KH, TDS)
- Supports an independent, ad-light site
Pricing FAQ
Will the free calculators stay free?
Yes. Every calculator, the product library, saved tanks on your device, calendar files and printable charts stay free.
Can I pay for Plus today?
Not yet. Plus is not launched and nothing is charged. Join the waitlist and we will email you once when it is ready.