Free membership · No password

Your tank,
remembered.

Sign in once and AquaCalc starts working in the background — watching shops for the plant you want, re-pricing your list every morning, charting your water and telling you what is due.

  • Free forever
  • No password
  • No ads or tracking
  • Delete anytime
12Free calculators
76Plant profiles
58Cited science guides
8UK shops watched daily
Stock alerts

It waits so you
don’t have to.

Watch any plant, stone or filter across every shop we track. When one of them puts it back on the shelf, you get one email — not a feed to check. Browse the comparison →

Saved lists

Your scape, priced
again this morning.

Build a list once. Every morning it is re-costed against every shop, line by line, with what is out of stock marked and the difference since you saved it shown honestly — like for like, not a total flattered by missing items.

Parameter log

One reading is
a number. Ninety
is an answer.

Log KH, GH, nitrate, pH and temperature per tank and watch them settle — or not. The log is where a change of routine stops being a guess and starts being visible.

Maintenance

Saturday. 40%.
You’ll be told.

A schedule built around your tank rather than a generic calendar, and an optional email each Sunday with the week ahead on it. One email. Off in a click.

Heat alerts

Four days’ warning,
not four hours’.

Give it a postcode and the heat forecast watches the real Met forecast for you. You hear about the hot spell while there is still time to do something about it.

Favourites

Everything you keep,
on one shelf.

Save any guide or plant profile, pin what you reach for most to the top, and see at a glance what has been added since you were last here.

Private by design

Your account earns us nothing.

There are no ads on AquaCalc and no third-party trackers. We do not sell data, and we never will. Every email has a one-click unsubscribe, and your settings page erases your account and everything in it. Read the privacy policy →

Three taps. No password.

  1. 1

    Enter your email

    One field. Nothing to invent, nothing to remember.

  2. 2

    Click the link we send

    It lands within seconds and is good for 15 minutes.

  3. 3

    You’re in — for good

    The account is made and stays signed in on that device.

Ready when you are

Free, ten seconds, and nothing to lose — you can erase the account and everything in it from your settings, whenever you like.