Shoal & Stem

The free aquarium app hobbyists actually use. Scan water tests, track your params, and ask Finn — your AI tank expert — anything. No subscription, ever.

Shoal & Stem is the all-in-one aquarium app — and it's 100% free. Track your water parameters, get advice from a personal AI, ID 1,500+ species, and journal every tank. No subscription. No paywall. Ever.

Most fishkeeping apps lock the good stuff behind a monthly fee. We don't.

TRACK EVERY PARAMETER Log pH, ammonia, nitrite, nitrate, GH, KH, temperature and more. Snap a photo of your water test and we'll read the values for you — then chart every reading over time so you catch trouble early.

FINN — A PERSONAL AI THAT KNOWS YOUR TANK Ask anything, like "Can I add a betta here?", and get answers grounded in your tank's real data: your species, your parameters, your setup. Tell Finn what you did in plain English and it logs it for you.

1,500+ SPECIES AT YOUR FINGERTIPS Fish, shrimp, snails, and plants — each with care guides, temperament, water needs, and stocking compatibility, so you buy with confidence.

JOURNAL EVERY TANK Document the journey with photos, notes, and milestones. Look back on how far your tank has come, from set-up day to fully grown in.

A LIVE HEALTH SCORE Every tank gets a health score that updates as you log — a simple read on how it's doing, with clear next steps when something needs attention.

UNLIMITED TANKS A single betta or a shelf full of aquascapes — track as many as you like. No limits, no tiers.

BUILT AROUND COMMUNITY Discover real tanks from keepers everywhere, follow along, and share your own.

Plus maintenance reminders, water-change scheduling, source-water profiles, and equipment tracking.

Beautiful, powerful, and completely free. Download Shoal & Stem and give your tank the care it deserves.