I Tested Fish Aquarium Tanks for 3 Months: Here's What Happened

Why I Decided to Test This

I'll be honest—I never thought I'd become the kind of person who obsesses over fish tanks aquariums. But there I was, six months ago, standing in my living room staring at a cloudy, algae-covered disaster that was supposed to be a peaceful underwater paradise. My kids had begged for fish for over a year, and I'd finally caved during the pandemic, thinking it would be a simple, calming hobby.

I was wrong. So wrong.

My first attempt at setting up a fish aquarium tank was a complete failure. Within three weeks, two goldfish had died, the water looked like pea soup, and my eight-year-old daughter cried every time she looked at it. I felt like a failure as a pet owner, even though we were only dealing with fish. The problem? I'd bought the cheapest tank at a big-box store, thrown in some gravel and decorations, filled it with tap water, and dumped the fish in the next day. Classic beginner mistakes, but I didn't know any better.

After that disaster, I decided to start over—but this time, I'd do it right. I committed to a three-month experiment where I'd test different fish aquarium tanks, learn proper setup techniques, and document everything. My goal was simple: create a thriving aquarium that didn't require constant emergency interventions and actually brought joy instead of stress.

My Starting Point

When I began this journey in early February, my situation was pretty grim. I had:

One failed 10-gallon tank sitting empty in my garage, still crusty with dried algae
Zero living fish (and a lot of guilt about that)
Approximately $150 wasted on my first attempt, including the fish, cheap equipment, and various "miracle" products I'd panic-bought
A family skeptical that I could make this work
No real knowledge about nitrogen cycles, filtration, or proper tank maintenance

My specific problems were:

I didn't understand that fish tanks aquariums need time to establish beneficial bacteria
I'd overstocked the tank immediately (five goldfish in a 10-gallon tank—yikes)
I had no idea about proper filtration or water testing
I'd bought the wrong type of tank for the fish I wanted to keep

My frustrations were mounting. I'd spent money, disappointed my kids, and killed innocent creatures through ignorance. I'm not typically someone who gives up easily, but I was close. The turning point came when a colleague mentioned he'd been successfully keeping fish for years and made it sound... easy? That conversation sparked something in me. If he could do it, surely I could figure it out too.

The Process: Week by Week

Week 1: The Difficult Start

I started my experiment on February 7th by joining three different aquarium forums and watching approximately 47 YouTube videos about fish tank setup. The information overload was real. Every expert seemed to contradict the last one. Some swore by undergravel filters, others called them death traps. Some said you needed expensive equipment, others kept beautiful tanks with minimal gear.

I decided to test three different fish aquarium tanks simultaneously to compare:

Tank A: A 20-gallon standard glass tank with a hang-on-back filter ($89)
Tank B: A 15-gallon cube tank with a canister filter ($145)
Tank C: A 10-gallon all-in-one kit with built-in filtration ($67)

My plan was to set up all three, cycle them properly (this time!), and see which performed best for a beginner trying to keep community tropical fish for aquariums freshwater.

Day 1 was exciting. I set up all three tanks in my basement, which my wife was thrilled about (sarcasm). I added substrate, decorations, and filled them with dechlorinated water. I also bought a proper water testing kit—something I'd skipped entirely in my first attempt.

Day 3 brought my first reality check. The water was crystal clear, which looked great, but my test kit showed zero ammonia, zero nitrites, zero nitrates. That sounds good, right? Wrong. It meant nothing was happening biologically. The tanks were sterile. I needed to add an ammonia source to start the nitrogen cycle.

I added fish food to each tank to decompose and create ammonia. Then I waited. And waited. This is the part nobody warns you about—the cycling process is boring. Nothing visible happens. You're just testing water and writing down numbers like some kind of chemistry student.

By day 7, I was already doubting myself. My test results were barely changing. Tank B showed a tiny ammonia reading (0.25 ppm), but the others showed nothing. I started worrying I'd done something wrong again.

Week 2-3: First Signs of Progress

Week two brought the first real changes. On day 10, all three fish aquarium tanks showed ammonia readings between 2-4 ppm. Progress! The fish food was decomposing, creating ammonia. Now I just needed beneficial bacteria to colonize the filters and convert that ammonia to nitrites, then nitrates.

I tested the water every single day, sometimes twice. My wife asked if I'd developed a new obsession. She wasn't wrong.

By day 14, Tank A (the 20-gallon with hang-on-back filter) showed the first nitrite readings. The bacteria were establishing! Tank B followed two days later. Tank C, the little 10-gallon kit, was lagging behind with barely detectable nitrites by day 17.

This was fascinating to me. All three tanks had the same water source, same temperature (78°F), and similar setups, but they were cycling at different rates. I theorized that Tank A's hang-on-back filter had more surface area for bacteria, while Tank C's smaller built-in filter was limiting bacterial colonization.

Week three brought the most dramatic changes. Tank A's ammonia started dropping while nitrites spiked to 5+ ppm (off my test chart's scale). This was actually good news—it meant the first stage of bacteria was thriving and converting ammonia to nitrites. Now I needed the second bacterial colony to convert nitrites to nitrates.

I also noticed my first algae growth—small brown patches on the glass of all three tanks. Old me would have panicked. New, slightly-more-educated me recognized this as diatom algae, completely normal in new tanks. I left it alone.

By day 21, Tank A showed its first nitrate readings (around 10 ppm) while ammonia and nitrites began dropping. We were getting close to a cycled tank!

Week 4: The Turning Point

Day 25 was my breakthrough moment. Tank A tested at 0 ammonia, 0 nitrites, and 20 ppm nitrates. The tank was cycled! It had taken about 3.5 weeks, which was apparently normal. I performed a 50% water change to reduce the nitrates and prepared to add fish.

This is where I made a crucial decision that changed everything. Instead of rushing to the pet store like last time, I spent three more days researching which freshwater aquarium fish would actually thrive in a 20-gallon tank. I learned that goldfish (my first choice) actually need way more space than most people think—at least 20-30 gallons per fish for fancy goldfish.

Instead, I decided to create a tropical community tank with:

8 neon tetras (small, peaceful, beautiful)
6 Corydoras catfish (bottom dwellers, algae eaters)
1 honey gourami (centerpiece fish)

On day 28, I added the neon tetras to Tank A. Just them, nobody else. I'd learned about adding fish gradually to avoid overwhelming the bacterial colony. I was so nervous. Every hour, I checked on them. They looked happy, swimming actively, exploring their new home.

I tested the water the next morning: 0 ammonia, 0 nitrites, 10 ppm nitrates. Perfect. The bacteria were handling the bioload.

Meanwhile, Tank B (the 15-gallon cube) finished cycling on day 30, and Tank C (the 10-gallon kit) finally cycled on day 35. The difference in cycling times was notable and taught me that larger tanks with better filtration really do establish faster.

Months 2-3: The Results

By week five, all three fish aquarium tanks were fully stocked and running smoothly. I'd added the remaining fish to Tank A gradually over two weeks, and everyone was thriving. I set up Tank B as a planted tank with lower light requirements and added a betta fish with some ember tetras. Tank C became a shrimp tank—something I'd never considered but became obsessed with after discovering how cool freshwater shrimp are.

Month two was when the real learning happened. I established routines:

Water testing: Twice weekly (down from daily)
Water changes: 25% every Sunday
Filter maintenance: Monthly cleaning in old tank water
Feeding: Once daily, small amounts

I also learned what happens when you mess up. In week six, I went out of town and asked my teenage son to feed the fish. He dumped in way too much food. I came home to cloudy water and an ammonia reading of 1.0 ppm in Tank A. My carefully established balance was disrupted. I did an immediate 50% water change, then another the next day, and stopped feeding for three days. The tank recovered within a week, but it was a good reminder of how delicate these ecosystems are.

By month three, something magical happened—I stopped worrying. The tanks had found their equilibrium. The water stayed clear with minimal intervention. The fish had established territories and routines. I could actually enjoy watching them instead of constantly troubleshooting problems.

I also noticed differences between the three tank setups:

Tank A (20-gallon standard) was the easiest to maintain. The larger water volume meant more stability, and the hang-on-back filter was simple to clean. This became my favorite.

Tank B (15-gallon cube) looked stunning with plants, but the canister filter was overkill and kind of annoying to maintain. The cube shape also made aquascaping harder than I expected.

Tank C (10-gallon kit) was cute but limiting. It worked great for shrimp, but I wouldn't want to keep fish in something so small. Less forgiving of mistakes.

The Concrete Results

Before (Day 0):

Living fish: 0.
Money wasted on failed attempts: $150.
Hours spent on emergency interventions: ~15/month.
Algae coverage: 60% of tank surfaces.
Water clarity: Cloudy/green.
Confidence level: 2/10.
Family enthusiasm: 3/10.

After (Day 90):

Living fish: 24 thriving across three tanks (+2400%).
Total investment in successful setup: $485.
Hours spent on routine maintenance: ~3/month (-80%).
Algae coverage: <5% of surfaces (minor, easily managed).
Water clarity: Crystal clear in all tanks.
Confidence level: 8/10 (+300%).
Family enthusiasm: 9/10 (+200%).
Ammonia levels: 0 ppm (consistently).
Nitrite levels: 0 ppm (consistently).
Nitrate levels: 10-20 ppm (safe range).

Unexpected Metrics:

Number of times my kids voluntarily did homework near the tanks: ~40.
Stress reduction (subjective): Significant.
New hobby friends made: 4 (through forums).
Plants kept alive: 12 species.

What I Learned (That Nobody Tells You)

Positive Surprises

Fish tanks aquariums are actually calming once established. During those first few weeks, I thought everyone who talked about the "relaxing nature of aquariums" was lying. But they weren't. Once the tanks stabilized, sitting and watching the fish genuinely reduced my stress after work. There's something meditative about it.
The hobby is incredibly deep if you want it to be. I started just wanting to keep fish alive, but I got sucked into aquascaping, plant keeping, breeding possibilities, and water chemistry. There's always something new to learn, which appeals to my personality.
Bigger is actually easier. This contradicts what I assumed. I thought a smaller tank would be simpler for a beginner. Totally wrong. The 20-gallon tank was far more forgiving than the 10-gallon because larger water volumes are more stable. Parameters don't swing as dramatically.
The community is incredibly helpful. I expected gatekeeping and judgment (this is the internet, after all), but the aquarium forums I joined were filled with people genuinely excited to help beginners. When I posted my cloudy water emergency, I had five detailed responses within an hour.
Fish have personalities. I didn't expect this. I thought fish were just... decorative? But my honey gourami clearly recognizes me and swims to the front of the tank when I approach. The Corydoras are goofy and social. The neon tetras have a hierarchy. They're more like pets than I anticipated.

Disappointments

The initial time investment is significant. Those first 4-6 weeks require daily attention and testing. You can't just set up a tank and leave for a two-week vacation. If you're not willing to commit to that initial period, don't start. I probably spent 30-40 hours in the first month between research, setup, and monitoring.
Quality equipment matters more than I wanted it to. I tried to cheap out on some things—a $15 heater, a basic light. Both failed within six weeks. I ended up spending more replacing them with quality versions than if I'd just bought the right stuff initially. My total investment of $485 could have been $400 if I'd made better initial choices.
Some fish are fragile despite being sold as "beginner fish". I lost two neon tetras in week seven to what I think was neon tetra disease. There was nothing I could have done—it's a genetic condition. But it still felt like failure. You have to accept that sometimes fish die, and it's not always your fault.
Plants are their own complicated hobby. I thought adding live plants would be easy and beneficial. Some plants were fine (Java fern, anubias), but others melted, turned brown, or got covered in algae. Plants need specific lighting, nutrients, and sometimes CO2. It's not as simple as "stick plant in gravel."
The hobby can get expensive quickly. Once you're successful, it's tempting to upgrade everything. Better lights, CO2 systems, automatic feeders, more tanks... I had to consciously stop myself from spending hundreds more on "nice to have" items.

Do I Recommend It?

YES, if:

You can commit to 4-6 weeks of daily attention during initial setup. This isn't a weekend project. You need to test water regularly, monitor parameters, and be present during the critical cycling phase. If you're looking for something that requires minimal effort, this isn't it.
You're willing to learn proper freshwater fish care before buying. Don't be like old me. Read guides, watch videos, join forums, and ask questions before you spend a dime. The learning curve is real, but it's manageable if you approach it systematically.
You have space and can commit long-term. Fish live for years. Some species live 10+ years. You're not just committing to setup—you're committing to ongoing maintenance, water changes, filter cleaning, and care. Make sure you're ready for that.
You want a genuinely rewarding hobby. Despite the challenges, this has been one of the most satisfying things I've done. Watching an ecosystem thrive, seeing fish develop personalities, creating a beautiful living space—it's worth the effort.

NO, if:

You want something completely hands-off. Aquariums require regular maintenance.
You're on a very tight budget. Initial setup costs money, and quality equipment is worth the investment.
You lack patience. Those first four weeks of cycling are tedious but necessary.
You're not willing to accept occasional failures. Sometimes fish die. It's part of the hobby.

Final Thoughts

Three months ago, I was standing in my living room staring at a dead tank and feeling like a failure. Today, I have three thriving aquariums, a new hobby I'm passionate about, and a family that gathers around the tanks to watch the fish every evening. My kids have learned responsibility, patience, and basic biology. My stress levels have genuinely decreased.

The journey from "why did I kill those goldfish?" to "I'm successfully maintaining multiple aquatic ecosystems" taught me that most "failures" are just lack of knowledge. I didn't fail at keeping fish—I failed at preparing properly. Once I committed to learning and doing things right, everything changed.