Aquarium Rescue
Red Gills in Aquarium Fish: Ammonia Burn, Low Oxygen, or Disease?
Red gills in aquarium fish can mean ammonia burn, nitrite, chlorine, low oxygen, parasites, or infection. Here is…
Aquarium Rescue School
Stop Your Fish From Dying.
Where it hurts
What’s going wrong in your tank?
Pick the problem you’re facing and jump straight to the rescue guide.
- Fish Dying Sudden or slow losses? Find the real cause before you lose more. Fix it
- Cloudy Water Milky, green, or hazy water — diagnose it and clear it for good. Fix it
- Algae Stop the green takeover and rebalance your tank the right way. Fix it
- Plants Melting Leaves dissolving or browning? Save your plants with the right fix. Fix it
- Low Oxygen Fish gasping at the surface? Boost oxygen before it is too late. Fix it
- Toxic Water Ammonia, nitrite, chlorine — find the hidden toxins poisoning your tank. Fix it
Fresh from the lab
Latest Rescue Guides
Step-by-step fixes for the problems hurting your tank right now.
- Aquarium Rescue
Fish Lying on the Bottom of the Tank: What to Check First
Fish lying on the bottom can be resting, stressed, cold, bullied, poisoned by ammonia, or sick. Here is…
- Aquarium Rescue
Fish Hiding and Not Eating: Stress, Water Quality, or Disease?
A fish hiding and not eating may be stressed, bullied, in poor water, or showing early disease signs.…
- Aquarium Rescue
Fish Acting Weird After a Water Change? What to Check First
Fish acting weird after a water change usually means temperature, chlorine, ammonia, nitrite, pH, or oxygen changed too…
- Aquarium Rescue
Fish Flashing: Why Your Fish Is Scratching and What to Do First
Fish flashing is the earliest sign of gill or skin irritation. Learn why clear water still causes it,…
- Aquarium Rescue
Fish Sitting in the Filter Output? Why It’s an Early Oxygen Warning
Fish parking in the filter outflow is usually oxygen-seeking — an early low-O2 warning. Learn to tell distress…
Free tools
Aquarium Tools
Simple calculators that take the guesswork out of fishkeeping.
- Water Change Calculator Work out the exact % and volume for a safe water change.
- Stocking & Bioload Guide Check whether your tank is overstocked for its size.
- Oxygen / Aeration Check Diagnose low-oxygen risk from temperature and stocking.
- Temperature Range Finder Find the safe temperature band for your fish.
Don’t lose another fish to a problem you could have caught early.
Get the free Aquarium Survival Checklist and spot trouble before it spreads.
Tested & trusted
Recommended Gear
The essentials we recommend to keep a tank healthy. Buy once, buy right.
Water Test Kit
The single most important tool for catching toxic water early.
See our pickDechlorinator
Neutralises chlorine and chloramine before it harms fish.
See our pickAir Pump & Stone
Cheap insurance against low-oxygen emergencies.
See our pick
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