Aquarium Toolkit

Your tank, its numbers, and the maths behind them, in one place. Open the app and your tank is there: its health at a glance (what's in or out of target, stability, drift, days since the last test and water change), what it's using each day, the latest readings against your target bands, your livestock and how they're growing, the next jobs, and the tank's whole history to scroll back through. TRENDS & DOSING • Every parameter over 7, 30 or 90 days, with dose changes, one-off doses and water changes on the same timeline, and your dose in mL/day underneath • Daily use of alkalinity, calcium and magnesium worked out from your tests with everything you added taken out, so it holds up across dose changes and water changes • Early drift flags ("Alk falling 0.05 dKH/day since Oct 19") and a stability score • The dose that holds the level, from your current mL/day and your solution's strength, and a correction plan capped at the change per day you choose, with the projected curve • Dose history showing how each change played out, demand over time as your corals grow, and the Ca:alk balance against calcium carbonate • Quick logging: big keypad, last values filled in, your test kit's units, and one tap for "same doses as yesterday" SALT & WATER • Salt mixing that works by mass, not by averaging SG: mix two waters, swap water out and back in (once or over several changes), raise with salt or lower with fresh water, or mix a new batch • Calibrate your own salt once and the gram figures match your mix • Salinity converter: SG on a 20/20, 25/25 or 60/60 scale, practical salinity and conductivity, using the UNESCO seawater equations • Water change maths, true water volume (bow-fronts, sump, plumbing, rock and sand) and top-off evaporation CHEMISTRY • Raise alkalinity, calcium or magnesium from the compounds themselves (bicarbonate, carbonate, calcium chloride, magnesium salts) or from your own solution's stated strength • Kalkwasser, freshwater hardness and CO₂, fertilizer ppm and a unit converter LIGHT • Light coverage with refraction at the water surface: footprint, fixture count, spacing and overlap • Daily light integral with ramps, beside published coral study values and editable starting ranges • PAR maps by date, and PAR at depth fitted from your own meter readings LIVESTOCK & GROWTH • A page for every coral, fish and invert: photo, placement pin on a photo of your tank, date added and source • Growth photos over time as a then-and-now slider or side by side, with a quick "add growth photo" from the home screen • Your own measurements (size, colony width, heads, polyps, frags cut) charted over time, and events: moved, fragged, colour notes, lost • Growth highlights on the home screen ("+2 cm since June") RECORDS • Test log with charts, target bands and natural seawater for reference • A history timeline of tests, doses, dose changes, water changes, livestock events and photos • Tank photos with a then-and-now slider • Maintenance reminders with notifications, cycling log, running cost, multiple tanks and CSV export Every tool explains itself the first time you open it, and the ⓘ buttons say what each field means and where the formula comes from. Works offline. No account, no ads, no tracking. Aquarium Toolkit does the maths on the numbers you enter. It gives no medication, disease treatment or livestock care advice. Test before and after any change, and make large changes in steps.