The aquarium is, without question, the most efficient passive money-maker in Fisch. Whether you’re grinding for XP, farming rare items, or just looking to build a setup that earns while you’re offline, the aquarium is where it all happens.
This guide breaks down everything you need to know to create the best aquarium possible, including the most profitable fish, the most effective rods, and the optimal strategies to boost your income and XP.
For context, I reached max level and became one of the richest players in Fisch almost entirely through aquarium optimization. So if you’re ready to turn your tank into a billion-credit business, here’s how to do it.
Step 1: Understanding the Setup
Here’s the first thing to know: your aquarium earns money both online and offline. That means every fish you add contributes to passive income, so each slot should be filled with purpose.
My current aquarium isn’t even my best version, yet it still earns millions daily. The goal is to maximize the value and multipliers of every fish, and to do that, you need to understand mutations.
Step 2: Best Mutations and Why They Matter
Mutations are the foundation of aquarium profit. They multiply your fish’s base value, and the higher the multiplier, the faster your money and XP grow.
The top-performing mutations right now include Master Supersized and Tryhard. These provide some of the highest multipliers in the game, for example, a 1 million-value fish with a Tryhard mutation jumps to 17 million.
However, the Tryhard Rod is nearly impossible to use legitimately; only exploiters or admin events can realistically yield Tryhard fish.
For normal players, the Evil Pitchfork Rod is the best alternative. It grants the Evil Mutation, which has a 15x multiplier and is actually attainable in-game. You can obtain it in the Crimson Cavern, and it’s one of the best rods for consistent profit.
Step 3: Catching High-Value Fish
To fill your aquarium with valuable fish, you’ll want to participate in Admin Abuse events, especially Mega Mayhem. These events offer the best opportunities to catch rare, mutated fish.
Focus on catching:
- Mastered Skylers
- Moss Lurkers
- Corrupted Krakens
You can also find Secret Moss Lurkers in the Forgotten Temple. Try using the Evil Pitchfork Rod during events to maximize your chances of landing strong mutations.
Step 4: Study What Other Players Use
Researching what other top players are using can save you time and help you copy proven setups. There are sites where players sell or showcase aquarium bundles, and these often reveal current meta picks.
Right now, the most common aquarium fish among high-level players include:
- Corrupted Floppies with Mastered mutations
- Scyllas (both normal and corrupted variants)
Both species are obtained from limited-time events like Ghastly Tide and Secret Storm, and they remain the most reliable fish for long-term profit.
Step 5: Appraising for Maximum Value
Before placing your fish in the aquarium, always appraise them at Treasure Island.
Use the Traveler’s Whistle from the Traveling Merchant to reach the island. Appraising adds a multiplier to your fish’s value, for instance, one of my Skylers received a 1.3x boost, significantly increasing its hourly profit.
It’s an easy step that many players overlook, but it can dramatically improve your total earnings.
Step 6: Combine Aquarium Profit with AFK Fishing
For even faster progress, run your aquarium while AFK fishing at Crystal Cove. Crystal Cove offers some of the best XP rates in the game, and combining active XP farming with passive aquarium income leads to massive returns.
Step 7: Choose Your Goal – Money, XP, or Items
Your aquarium can be specialized depending on your primary goal. Each setup focuses on a different type of gain:
| Goal | Focus | Benefit |
|---|---|---|
| Money | High-value, heavy fish | Maximum credits per hour |
| XP | High-base-XP fish | Fastest leveling |
| Items | Fragments and Relics | Consistent loot farming |
Let’s break down how each works.
Item Setup – Best for Relics, Totems, and Loot
If your goal is material farming, focus on rarity. Item profit is calculated as:
Item profit = rarity × base rate per hour
| Rarity | Items per Hour |
|---|---|
| Trash | 1 |
| Common–Uncommon | 2 |
| Rare–Special | 4 |
| Mythic | 6 |
| Gemstone | 8 |
| Relic | 9 |
| Fragment | 10 |
The ideal layout is:
- 5 Fragments (Ancient, Deep Sea, Earth, Solar, Glacial)
- 3 Relics (Exotic, Cosmic, Normal)
This combination yields up to 77 items per hour, the current maximum. Even partial sets can achieve around 60–70 per hour, and item farming continues even when you’re offline.
XP Setup – For Leveling Fast
XP gain in the aquarium equals 20% of the fish’s base XP per hour.
That means fish with the highest base XP will give the best aquarium XP.
Best options include:
- Colossal Ethereal Dragon (~700,000 XP base)
- Elder Mossjaw (~700,000 XP base)
- Scylla (~500,000 XP base)
- Corrupted Floppy (~430,000 XP base)
Avoid placing duplicates, XP output is reduced if you use multiple copies of the same fish.
Money Setup – For Maximum Hourly Credits
If your main goal is money, your income is determined by a combination of value, weight, and multipliers.
Hourly profit = (Fish value × Weight × Multipliers) ÷ 5
Factors include:
- Fish base value and weight
- Shiny or Sparkling traits (each adds ×1.5)
- Food multipliers
- Unique species (duplicate penalties apply)
Mutations like “Big” or “Giant” are less efficient than value-based multipliers. The best fish for money are typically those with high base prices and large size potential.
Recommended fish:
- Mythical Megalodon
- Ethereal Dragon
- Scylla or Corrupted Scylla
Step 8: Understanding Profit Caps
You may have seen claims of players making 100 million per hour, but those days are gone. The developers introduced rebalancing to prevent broken setups.
Realistic profit ranges:
- 5–10 million per hour for standard optimized aquariums
- 15 million+ only through special events or rare gear
That still translates to billions per week for dedicated players, entirely passive once your aquarium is fully optimized.
Final Summary
| Goal | Focus On | Example Fish |
|---|---|---|
| Items | Fragments + Relics | Ancient Fragment, Deep Sea Fragment |
| XP | High-Base-XP Fish | Elder Moss Jaw, Colossal Ethereal Dragon |
| Money | Heavy, High-Value, Sparkling Fish | Skyler, Corrupted Floppy, Mythical Megalodon |
Wrap-Up
Building an optimized aquarium in Fisch isn’t just about luck, it’s about strategy. With the right combination of rods, mutations, and fish, your aquarium can generate consistent XP and money without any active fishing.
Focus on attainable mutations like Evil, prioritize high-value or high-XP fish, and always appraise your catches before placing them in your tank. Combine this with occasional AFK fishing, and you’ll steadily build a setup that earns billions over time.
Experiment with different combinations, keep an eye on new event fish, and refine your layout as you go. Eventually, your aquarium will do all the work for you, and that’s when you’ll know you’ve mastered Fisch. Up next, check out our rod progression guide in Fisch in the Second Sea if you’re still struggling on some parts.
