Most aquarium apps are notebooks — you write the numbers down and you are still the one who has to know what they mean. AquaHelm reads them against the fish you actually keep.
Every species tolerates a range. Put several in one tank and the water has to suit all of them at once, so the target is the overlap — and sometimes there isn't one.
Paracheirodon innesi — neon tetra, above. Labidochromis caeruleus — yellow lab, below.
No overlap. These two cannot share water, and AquaHelm says so before you run a single test — not after something goes wrong.
It is toxic at any detectable level, whatever lives in the tank. That is a property of water, not of fish, so no stocking choice and no manual setting can turn the warning off.
With no fish in yet, ammonia is feeding the bacteria you are growing and large water changes set you back. With fish in, the same reading is burning their gills today. AquaHelm knows which tank you have.
Chemistry tells you which stage you are at. Only time tells you whether you are stuck on it — and then the usual culprit is carbonate hardness, long before pH looks wrong.
Water above target is never the heater's fault — it is already off. The room is warm, or the lights are. Different problem, different fix.
A schooling species kept in threes, or a fish that needs four times the tank you have — both are findings that need no water test at all.
The built-in catalogue will never cover everyone's tank. Add a species yourself, leave blank whatever you do not know, and it joins the calculation like any other.
No account. No sign-in. AquaHelm makes no network requests at all — your tanks, your readings and your stock stay on your phone, and there is nowhere for them to go.
That is not a policy we promise to keep. It is what the app is: there is no server, no analytics, and no advertising in it. The privacy policy says the same thing at more length.
In development, for iPhone. Freshwater first — temperature, pH, ammonia, nitrite, nitrate and hardness — with a catalogue of common species and a verdict built on top of them.
A closed beta is coming. If you keep fish and would like to break it early, get in touch.