Question About Goldfish Behavior and Tank Setup

Hello fellow fish enthusiasts,

I have a few questions about my goldfish and their care, and I’d really appreciate your help!

I recently got two goldfish and am currently keeping them in a 10-gallon tank. They seem healthy, but I’ve noticed some unusual behavior recently, and I'm a bit concerned.

1. Why do my goldfish occasionally swim in circles or seem to "chase" each other? Is this normal behavior or could it be a sign of stress or illness?

2. Tank Size: I’ve read that goldfish need a lot of space to thrive. Is 10 gallons enough for two goldfish, or do I need to upgrade the tank size? I want to make sure they’re comfortable.

3. Feeding: How much and how often should I feed my goldfish? I’ve been feeding them once a day, but they seem to eat quickly. Should I give them more food or split it into two feedings?

4. Water Quality: I’ve been doing weekly water changes and testing the water parameters. Is there anything else I can do to maintain excellent water quality for my goldfish?

I really want to make sure I'm providing the best possible care for them, so I’d love to hear any tips or advice from other experienced goldfish owners.

Thanks in advance!