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As you build your dream Vault inFallout Shelter, you’ll need to gather resources you can use to keep your Dwellers alive and happy. Water is a precious resource, but it’s contaminated by wasteland radiation. You’ll need to set up rooms to clean the water so that Dwellers don’t get sick.
As your Vault grows, there are two major rooms that can do this for you: the Water Treatment room and the Water Purification room. While they have similarities, they are different. Here’s everything you need to know to design your Vault using these rooms to their full potential in Fallout Shelter!

Pros And Cons To Water Treatment Rooms
Water is avital resource for Dwellers, but it’s unfortunately contaminated. Thankfully, you canget more waterthat’s cleanin the right rooms. You’ll immediately have access to the Water Treatment rooms, whichcost about 100 bottle capsto start building.
The price will increase with each additional Water Treatment room you add.

Pros
The primary pros to the Water Treatment room are thecost and ease of access. You can startbuilding and upgrading roomsright away to increase your storage and output.
As your Vault grows, you’ll needmore water to support your Dweller population. A steady supply of waterprevents Dwellers from getting irradiated, and an excess will heal radiation damage.

Cons
The downside to the Water Treatment room is that it canbecome outpaced and expensiveif you find yourself constantly running out of water.
You’ll need tofill the room with Dwellersthat have ahigh Perception stat, and even then it will take time for them to produce water.
Triple Room:1500
Pros And Cons To Water Purification Rooms
Once youincrease your Vault population to 80 Dwellers, you may start building Water Purification rooms. These rooms represent thenext tier of water production, making them a beneficial addition to your Vault. However, there are both pros and cons to be aware of.
The pros to Water Purification rooms start with the increased output. Whilenot a significant difference, it can quickly add up if you regularly check your Vault. Your Vault will seemore water with each collection, which helps combat radiation damage in the Vault.
The majordownside is the high cost. With how much it costs to build the room, let alone upgrade it, you’re better offwaiting for the Nuka-Cola Bottlerroom, which produces food and water together.
Triple Room:18,000
Is The Super Purification Plant Better Than The Water Treatment Plant?
Overall, theWater Purification room is slightly betterthan the Water Treatment Plant, but it comes at a high cost. Rather than build an expensive Water Purification room and try to upgrade it, you can use the Water Treatment rooms tohold out until you can unlock the Nuka-Cola Bottler.
Getting to the point where you unlock the Nuka-Cola Bottler can take some time, so if you want to ensure you always have the most efficient output for production, you may want to switch to the Water Purification room. If you’re just playing more casually or not worried about resources stick with the Water Treatment.
Since thestorage is the samefor both the Treatment and Purification rooms, there’sno benefit other than the outputof resources. If you check back into your Vault regularly, this canmake a small difference. It’s only worth the investment if you’renot strapped for bottle caps.