Gillwise: Aquarium Care
Fish tank water & care log
Free · Designed for iPad. Not verified for macOS.
Gillwise is the aquarium companion that actually understands your tank. Log a water test and it tells you - in plain English - whether each number is fine or a problem for the specific fish you keep. Add a species and it warns you about conflicts before you bring it home. Everything works offline, with no account, no ads, and no subscription. Buy it once and it's yours.
WATER TESTING THAT THINKS
Record ammonia, nitrite, nitrate, pH, temperature, GH, KH, salinity and phosphate. Instead of just storing numbers, Gillwise grades every reading good, caution, or action-needed - measured against the overlapping needs of the species actually in that tank, not a generic chart. Each result comes with clear guidance on what it means and what to do, plus a recent-trend view so you can see nitrate creeping up before it becomes algae.
STOCK SMARTER
Build your stocking list from a built-in library of 145 fish, invertebrates, plants and corals. Gillwise estimates your bioload and checks compatibility automatically:
• Fin-nippers housed with long-finned tankmates
• Predators kept with fish small enough to eat
• Shoaling species kept in groups that are too small
• Dwarf shrimp at risk from larger fish
• Saltwater species dropped into a freshwater tank
• Temperature and pH needs that simply don't overlap
A 145-SPECIES CARE LIBRARY
Every entry includes temperature, pH and hardness ranges, minimum tank size, adult size, temperament, diet, care level and real husbandry notes - for freshwater tropical and coldwater fish, brackish and marine fish, shrimp, snails, plants and reef corals. Search it, filter it, and add any species straight to a tank.
NEVER MISS MAINTENANCE
Set up recurring tasks - water changes, water tests, filter rinses, substrate vacuuming, dosing - and Gillwise shows you what's due or overdue at a glance. New tanks get a sensible starter schedule for their type.
BUILT FOR EVERY TANK
Freshwater tropical, coldwater, brackish, saltwater fish-only and reef. Switch freely between °F/°C and gallons/liters.
PRIVATE BY DESIGN
Gillwise keeps everything on your device. No account to create, no ads, no tracking, and your data never leaves your phone. It doesn't even ask for a single permission.
Gillwise provides general aquarium husbandry guidance and is not a substitute for veterinary care or your own research into your specific livestock.
- More apps by Robert Corbin: https://apps.apple.com/developer/id1890247992
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Version 1.1
- Parameter history chart - see any of your 9 logged parameters (pH, ammonia, nitrite, nitrate, temperature, GH, KH, salinity, phosphate) on a real line chart. Choose 7-day, 30-day, 90-day, or all-time windows. Min, max, and latest stats shown beneath the chart.
- Nitrogen Cycle Tracker - for new tanks under 6 weeks old, Gillwise reads your ammonia, nitrite and nitrate history and tells you which phase you're in: Ammonia Spike, Nitrite Spike, or Cycled. Plain-English guidance for what to do next at every stage.
- Smart test pre-fill - opening "Log water test" now pre-fills every field from your most recent reading. Just update the values that changed.
The developer, Robert Corbin, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Robert Corbin
- Size
- 4.2 MB
- Category
- Lifestyle
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Robert Corbin