Know Your Tank.
Protect Your Fish.
Before you add a fish, Aquabuildr tells you if it belongs. It weighs compatibility, temperament, group size, water chemistry and remaining space against your current tank — so you find out at the store, not after.
What Aquabuildr does
Four things, and your fish depend on all of them.
Tanks rarely crash. They drift. Losses build quietly — a mismatch here, a parameter creeping there — until one morning it's obvious. Aquabuildr catches the drift before it becomes a real problem.
Tank Health Score
Your tank, scored out of 100, every day.
Every tank gets a live health score built from the things that actually kill fish: ammonia, nitrite, nitrate, pH, and whether you are keeping up with your own water-change schedule. It drifts down gently when you fall behind and recovers quickly when you catch up. Tap it and it tells you the single most useful thing you could do next.
- Skipping maintenance won't tank your score. Missed tests and late water changes can drop you to 40 at worst. Only genuinely unsafe readings take you below that.
- One clear next step. "Do This Next" tells you the single most important thing to do right now — not a list of chores.
- New tanks get a grace period. No score and no warnings while your tank is still settling in — just simple prompts until there's enough data to judge it fairly.
- After 60 days, your tank is treated as established. Ammonia and nitrite readings stop counting against you once it's cycled.
How the compatibility engine works
It doesn't compare numbers. It knows which fish actually live together.
Every species carries its own temperature, pH, hardness, minimum tank size, temperament and swim-level data — and its own vetted list of tank mates.
Tank Buildr
Plan the whole tank first. We'll catch the problems while it's still just a plan.
Pick a volume, add fish, and watch the compatibility list respond. Conflicts surface the moment they appear — with the reason, not just a red cross.
- Live used-space and available-space readout
- Warnings before you buy, not after
- Resume a half-built tank whenever you like — drafts are saved as you go
- Your first tank is free. Premium unlocks unlimited tanks and the multi-tank health view
Tank details
Six tabs, one complete picture of your tank.
Parameters, dosing, inhabitants, equipment, notes and tasks each live on their own tab — but they don't sit in silos. Aquabuildr reads across all six and turns them into one health score, pinned to the top of every tab, so you always know where the tank stands and what's driving it.
Your safe pH, temperature and hardness ranges are calculated from the stock you actually chose, not a generic chart. Imperial or metric, your call.
Filter Recommendr
We don't just ask how big your tank is. We ask what lives in it.
Built by aquarists, for aquarists.
Eight questions. 1,704 tank scenarios behind them.
Every aquarium is different, so a generic tank-size rating gets you a generic answer. Filter Recommendr weighs your bioload, stock, feeding habits, maintenance rhythm and setup against 1,704 modeled tank configurations, then matches yours to the filtration that actually fits it — not the one on the box.
Discussions
Ask the room. Keep the answer that actually worked.
A question board for people who already know your tank. Post the problem with photos or video, get answers from keepers who have solved it, and let the votes sort the useful from the confident.
- Vote answers up or down — the one that worked rises
- The asker marks one answer accepted, so the thread ends with a conclusion
- Comment under any answer to follow up without derailing the thread
- Filter by Latest, Most Viewed or Unanswered — and by open or closed
Inside the app
Designed by aquarium keepers, for aquarium keepers.
Premium
Free lets you record. Premium helps you protect.
Your first tank, the health score and every planning tool are free forever. Premium is the part you feel when one tank becomes four.
See what's in Premium
Protect your fish. Prevent costly mistakes.
Free to download on both stores. Build a tank in five minutes and find out what your local store should have sold you.
Have some questions?
Share your thoughts and we'll get back to you by email as soon as we can.