Lesson 1: Choosing the Right Tank Size and Location

Size and Location: Getting It Right from the Start

Choosing your tank is the first real decision you'll make, and it sets the tone for everything that follows. I'm going to be honest — my first tank was way too small, and I regretted it within a month. Let me help you skip that frustration.

What Size Tank Do You Need?

For guppies, here's my recommendation:

• Minimum: 10 gallons — Enough for 5-6 guppies with room to swim
• Ideal: 20 gallons — More stable water, more room for plants, and space to grow your group
• Avoid: Anything under 5 gallons — Too small for guppies to thrive. Water quality is nearly impossible to manage.

Here's something counterintuitive: bigger tanks are actually easier to maintain. More water means more stability. A small spike in ammonia in a 5-gallon tank is a crisis. In a 20-gallon tank, it's barely a blip. I learned this the hard way.

The Rule of Thumb

A common guideline is roughly 1 gallon per inch of adult fish. Guppies reach about 1.5-2 inches, so a 10-gallon tank comfortably holds 5-6 guppies. But honestly, more space is always better — especially if you think you might get "just a few more" (you will).

Where to Put Your Tank

Location matters more than most people realize. Here's what to consider:

• Away from direct sunlight — Sunlight causes algae blooms. A little indirect light is fine, but avoid windowsills.
• Away from drafts — Near doors, windows, or vents can cause temperature swings.
• On a sturdy surface — Water is heavy! A 10-gallon tank weighs about 85 pounds when full. A 20-gallon is over 170 pounds. Make sure your furniture can handle it.
• Near a power outlet — You'll need to plug in a filter, heater, and light.
• Somewhere you'll see it — You want to enjoy your tank! Put it where you spend time so you can watch your fish and spot problems early.

Tank Shape

Go for a standard rectangular tank. They have more surface area for gas exchange than tall, narrow tanks. Guppies also prefer horizontal swimming space over vertical.

What I Wish I'd Known

Once your tank is full and set up, it's really hard to move. Take an extra day to think about placement before you start filling it. Also, put a towel or a tank mat underneath to protect your furniture and cushion the glass.

Next up: Lesson 2 — Essential Equipment