Water & Cycling | GoodFishTank

What Temperature Should a Fish Tank Be? A Chart by Species
What temperature should a fish tank be? A sourced chart for goldfish, bettas, guppies, tetras and shrimp, the range your fish share, and when to worry.
How Much Aquarium Salt per Gallon? Doses, a Chart and When to Skip It
How much aquarium salt per gallon? Gram chart for 5 to 75 gallon tanks, why doses differ 5x, and which fish and plants may not take salt.
Fishless Cycle Stalled? Why It Stops and How to Restart It
Fishless cycle stalled? Check pH and alkalinity first, then ammonia, nitrite, filter cleaning and chlorine. What the sources say, and where they disagree.
Aquarium pH: What's Fine, When It Matters and When to Leave It Alone
What pH should a fish tank be? Most fish cope with tap water from 6.5 to 8.5. When a falling or high pH does matter, and how to move it safely.
Chlorine and Chloramine in Tap Water: Do You Need a Dechlorinator?
Yes, tap water needs a conditioner for fish. Chlorine fades in days, chloramine doesn't. How to dose it for water changes and why tests can mislead.
How Often to Change Aquarium Water: 25% a Week, Then Test
How often to change aquarium water: start at 10-25% a week, then let a nitrate test set the schedule. Plus when 50% is fine and when a big change hurts.
Cycling a Tank With Fish in It: How to Keep Them Alive While It Cycles
How to cycle a tank with fish already in it: how many fish, how little to feed, when to change water and how to tell it's done. With sourced numbers.
Safe Nitrate Levels for Aquarium Fish: Why Sources Say 20, 40 or 80 ppm
What is a safe nitrate level in a fish tank? Sources say 20, 40 or 80 ppm. Why they differ, which unit your test kit reads and how to lower nitrate.
High Nitrite in a Fish Tank: What to Do Tonight and How Much Is Too Much
High nitrite in your fish tank? Change a lot of water, add air and feed less. What the numbers mean, how salt helps and why the spike happened.
High Ammonia in a Fish Tank: Find the Cause, Then Fix It
Ammonia reading above zero? Test your tap water, check pH, then change 50% or more. Causes in new and old tanks, and what Prime does and doesn't do.
How Long to Cycle a Fish Tank: 4–6 Weeks, or Days if Seeded
How long it takes to cycle a fish tank: 30 to 45 days unseeded, days with established filter media. What speeds it up, what slows it and what doesn't help.
How to Tell If Your Tank Is Cycled: The 24-Hour Ammonia Test
How to tell if your fish tank is cycled: the 24-hour ammonia test, the numbers each source uses, readings that fool people, and what to do next.
Fishless Cycle: The Exact Ammonia Dose and Day-by-Day Schedule
Fishless cycle step by step: what you need, how much ammonia to add for your tank size, the day-by-day schedule and how to tell when it's done.
Aquarium Nitrogen Cycle: The Microbes Most Guides Get Wrong
The aquarium nitrogen cycle explained: how ammonia becomes nitrite, then nitrate, which microbes do it, what they need and how to read it on a test kit.