How to Use Water Flow to Unlock Hidden Rooms in Blue Prince

If you’ve been wandering the ever-shifting estate of Blue Prince, you’ve probably encountered the Pump Room and realized—yep, there’s a lot more to this water system than just turning a few levers. Welcome to your ultimate guide to understanding how the game’s water-connected rooms (Fountain, Reservoir, Aquarium, Kitchen, Greenhouse, and Pool) work—and how to use them to your advantage.

This guide covers how each of these rooms interacts with water, what secrets they hide when drained or filled, and how you can tap into the community for tips and solutions.


🚰 First Things First: How the Pump Room Works

The Pump Room is the central hub where you can redistribute water across the estate. You’ve got:

  • Six buttons for each key location: Fountain, Reservoir, Aquarium, Kitchen, Greenhouse, and Pool

  • Pipes and tanks connected to levers that manage where water goes

  • A diagram on the wall that shows how water flows between the tanks and areas (seriously—check it often)

Once you’ve got the hang of flipping levers and monitoring tank levels, you’re ready to start uncovering the secrets hidden beneath the water.

💡 Tip: Adjustments to the Pump Room are persistent. What you do one day may affect access routes or secrets the next!


Hidden Rooms, Blue Prince
🏛️ Fountain – Hidden Staircase to a New Zone

The Fountain is more than just a nice view. If you drain the water, you’ll reveal:

  • A hidden staircase leading to a secret chamber beneath the estate

  • A shortcut to the Antechamber basement

  • Access to lore-rich items and keys that are otherwise unreachable


💧 Reservoir – The Water Gate Between East and West

This one’s a biggie. Draining the Reservoir lets you:

  • Cross to the eastern half of the Underground

  • Discover the Sanctum Key (you’ll need to mess with the Boiler Room first)

  • Unlock shortcuts between boat docks and the Reservoir Control Station

📺 Watch a walkthrough on draining the Reservoir and unlocking the Sanctum


🐟 Aquarium – Not Just for Eels

The Aquarium is more than just a pretty underwater scene. When properly managed:

  • It powers certain puzzles if you have the Electric Eel upgrade

  • Draining it lets you move through maintenance tunnels

  • Filling it again can activate hidden conduits or switches

💬 Reddit Post: "What the heck do I do with the Aquarium?"


🍳 Kitchen – A Hidden Inventory Cache?

Yep, the Kitchen can be drained too. Doing so reveals:

  • An unmarked floor hatch that leads to a utility tunnel

  • Optional lore items (like Old Staff Notes)

  • Bonus stash pickups for later runs

It’s a subtle one, but worth the water.


🌱 Greenhouse – Grow Those Secrets

This one’s fun. If you fill the Greenhouse with water for several days, you'll start to notice:

  • Massive plants growing, creating new climbing paths

  • A hidden ledge with a rare gear item behind a large vine

  • Small animals that trigger pressure plates nearby

🧠 Community wisdom: “Water it for 3 days straight and you’ll get something new every time.”


🏊 Pool – Dive Into Depths of Loot

Ah yes, the Pool. Looks innocent enough, but once drained:

  • Reveals a secret door underneath the diving platform

  • Contains a rare collectible set

  • May give you access to a shortcut into the Conservatory

It’s one of the trickier ones to drain—requires redirecting water into Tank 2 using the right sequence of lever flips.


🧠 Common Mistakes & Community Advice

A lot of players struggle with the Pump Room system at first. Here's what we've learned from others:

  • Mixing up Tank 1 and Tank 2 is super common. Use the diagram!

  • If you can’t drain an area, check if another one is already full—you might need to empty it first.

  • Levers can be bugged if you interact with them too quickly after waking up—wait a second or two.


🔗 More Resources & Related Guides

Need help with more puzzle-heavy parts of the game? Check out these:


✅ Final Thoughts

There’s a lot more going on in Blue Prince than meets the eye—and that’s especially true with its water-connected rooms. By learning how to master the Pump Room and experiment with the game’s water mechanics, you’ll unlock more secrets, find rare items, and maybe even uncover paths that most players miss.

Got a new discovery or cool trick? Share it with the community!

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