Question 1

How often should I change water in a betta tank?

Accepted Answer

In a cycled, filtered betta tank of 5 gallons or more, change about 20-30% of the water every 1-2 weeks. Smaller or unfiltered tanks usually need more frequent changes.

Question 2

Can I leave my betta in the tank during cleaning?

Accepted Answer

Yes. For a normal partial water change, it is usually best to leave your betta in the tank and avoid unnecessary handling.

Question 3

Can I use tap water for a betta tank?

Accepted Answer

Yes, as long as you treat it first with a water conditioner. Tap water contains chlorine or chloramine, which are toxic to fish even in small amounts. A water conditioner neutralizes both within minutes. Don't rely on letting the water sit out. Most municipal water now uses chloramine, which doesn't evaporate the way plain chlorine does. A conditioner is the only reliable fix.

Question 4

How much water should I change at one time?

Accepted Answer

For routine maintenance, 20-30% is a good target in a stable tank.

Question 5

Do betta tanks need to be cleaned if the water looks clear?

Accepted Answer

Yes. Clear water can still contain ammonia, nitrite, and nitrate. Water quality should be judged with testing and routine maintenance, not appearance alone.

Question 6

How long should you let water sit before adding a betta fish?

Accepted Answer

If you're using a water conditioner, you don't need to let it sit at all. The conditioner makes tap water safe for fish within minutes by removing chlorine and chloramine. The old advice about letting water sit overnight came from a time when plain chlorine was the main concern. Chlorine does evaporate, but most tap water today uses chloramine, which doesn't. A conditioner is the only reliable fix regardless.

Now, if you're setting up a brand new tank, it'll need three to eight weeks to grow the good bacteria that keep ammonia and nitrite from building up. You can find all the details in our fish tank cycling guide.

Tanks

All Tanks guides

How to Clean a Betta Fish Tank: Water Changes & Maintenance

How to Set Up a Betta Tank: A Complete Equipment and Setup Guide

How to Cycle Your Betta Tank: A Beginner’s Guide to the Nitrogen Cycle

What Size Tank Do Bettas Need?

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