What No One Tells You Before Buying Your First Tank

When I bought my first aquarium, I thought it would be simple... a tank, some water, a few fish, and done. I had no idea how many small details there were that could make or break the whole experience.

Don’t get me wrong — fishkeeping is one of the most relaxing and rewarding hobbies I’ve ever picked up. But looking back, there are definitely a few things I wish someone had told me before I spent my first penny.

Here are the big ones...

1. Don’t rush to buy the tank first

I know it’s tempting — most of us start by spotting a gorgeous aquarium in a shop and thinking, "That’s the one I want!" But before you pull out your wallet, take a moment to plan.

Your tank size affects everything that follows: the type of fish you can keep, the heater and filter size, the stand, even where it’ll fit in your home. If you buy the wrong one on impulse, you might box yourself into limits you didn’t expect.

It’s far better to choose your fish first, plan your setup around them, and then buy the right tank to match.

2. Those "starter kits" aren’t always good value

I learned this one the hard way. The box said "Everything you need to start your aquarium!" — but half of it wasn’t suitable long-term.

The filter was too small, the heater too weak, and the light barely bright enough to see the fish, let alone grow plants. Within weeks, I was upgrading everything anyway.

Sometimes it’s cheaper — and far less frustrating — to choose your equipment separately so you get gear that actually lasts.

3. Patience is your secret superpower

Fishkeeping isn’t about instant results. The biggest beginner mistake is adding fish too soon.

New tanks need time to stabilise — water chemistry, bacteria growth, filtration… it all takes a little while to balance. When you rush, problems like cloudy water or stressed fish appear fast.

Give your tank time to "settle in" before adding anything alive, and you’ll save yourself a lot of heartache.

4. Not every fish gets along

Here’s another surprise: just because two fish are small doesn’t mean they’ll play nicely together. Some species nip fins, others need more space, and some simply have totally different water preferences.

A little research before buying makes all the difference, and keeps your tank calm and peaceful instead of turning into an underwater battleground.

5. You don’t need to spend a fortune

One of the best things about this hobby is that you can start small and build up slowly. A simple 15–25 gallon tank with a few hardy fish and a quality filter can look absolutely amazing.

You don’t need fancy gadgets, CO₂ systems, or designer tanks... you just need the right essentials to get started confidently.

The part no one tells you...

When everything’s running smoothly and your fish start exploring their new home, it’s a genuinely rewarding feeling. It’s calm, beautiful, and oddly addictive in the best way.

But it’s much easier to reach that stage when you start with a clear plan — knowing what to buy, what to skip, and when to add each piece.

Ready to plan your first aquarium the right way?

Before you buy a single thing, grab my free Freshwater Aquarium Equipment Checklist — it walks you through exactly what you’ll need (and what you won’t).

It’s the list I wish I’d had when I started.

👉 Download your free checklist here.

Already got the checklist?

Once you’ve gone through the checklist and picked out your gear, my beginner’s guide Fin-tastic Beginnings: Essential Equipment For Your First Aquarium looks at the equipment you need in much more detail.

Psst... Use code SAVE10 at the checkout to get the eBook for $9 rather than the regular price of $19!

Or, if you download the free Freshwater Aquarium Equipment Checklist and join the mailing list, you may find an even better welcome offer in the first email... ;)

Find out more about the eBook by clicking the image below: