Lesson 3: Choosing Your First Guppies (Males, Females, Ratios)

Picking Your First Guppies

This is the fun part — actually choosing your fish! But before you grab the prettiest ones you see, there are a few things worth knowing. I made some mistakes here that I want to save you from.

Males vs. Females: What's the Difference?

Telling males and females apart is actually pretty easy once you know what to look for:

• Males: Smaller body, vibrant colors, large flowing tails, and a pointed anal fin (called a gonopodium)
• Females: Larger body, more muted coloring, shorter tails, and a fan-shaped anal fin

Most pet stores have them separated, but double-check. I once came home with what I thought were "all males" and ended up with surprise babies three weeks later!

The Ratio Rule

If you're keeping males and females together, the golden rule is at least 2-3 females per male. This spreads out the males' attention so no single female gets chased relentlessly.

Your options:

• Males only: Beautiful, colorful, no babies. Some occasional chasing between males, but generally peaceful.
• Mixed group: Natural behavior, but expect babies. Use the 1:2 or 1:3 ratio.
• Females only: Less colorful, but calm and easy. Note: females from pet stores may already be pregnant!

How to Spot Healthy Fish at the Store

This is something I wish someone had walked me through:

1. Look at the whole tank — if several fish look sick, don't buy any from that tank, even the healthy-looking ones.
2. Watch for active swimming — healthy guppies are curious and moving.
3. Check the fins — they should be spread out, not clamped or ragged.
4. Look for clear eyes — cloudy eyes can indicate illness.
5. No visible spots or fuzz — white spots (ich) or cottony growth means disease.

How Many to Start With?

For a 10-gallon tank, I'd suggest starting with 5-6 guppies. This gives you a nice little group without overcrowding. You can always add more later once you're comfortable.

A common beginner mistake is buying too many fish at once. Start small, make sure your tank is stable, then add more gradually.

Where to Buy

• Local fish stores (LFS): Usually healthier fish and better advice than big chain stores.
• Chain pet stores: More convenient, but quality varies. Inspect carefully.
• Online breeders: Great for specific varieties, but shipping can be stressful for fish. Better once you have some experience.

What I Wish I'd Known

Don't buy guppies the same day you set up your tank. Your tank needs to cycle first (we'll cover this in Lesson 6). I know it's hard to wait, but your fish will thank you for it.

Next up: Lesson 4 — Basic Water Parameters Guppies Love