Pool's Closed

Difficulty: Hard

Pool's Closed is an achievement unlockable on iPhone, iPad, PS Vita, Android, and Nook. In order to unlock this achievement, you must pick plants that can shoot in more than one lane such as Starfruit/ Threepeater/Gloom-shroom for example (except Cattails as they're aquatic).

Strategy
An easy way to complete this Achievement is to play Level 3-1 on the second time you play Adventure Mode or quick play. When picking your plants, you should pick the following:
 * Sunflower
 * Threepeater
 * Wall-nut
 * Repeater
 * Cherry Bomb
 * Peashooter
 * Starfruit
 * Snow Pea
 * Chomper





You should focus on planting the Threepeaters in the 2nd and 5th rows. This way, you can damage the Ducky Tube Zombies that swim down the pool. If zombies are coming too close to the edge of the pool, wait for them to activate a Pool Cleaner, or plant a Cherry Bomb in the row next to them (as it is an area of effect attack that will hit zombies in the pool). If zombies on land are getting too close, stop them by planting Peashooting plants, or defensive plants (such as Wall-nuts or Tall-nuts). A Gloom-shroom is technically cheaper than a Threepeater (it costs 25 Sun less if the Fume-shroom and Coffee Bean are also included), so it is a good idea to provide extra protection in the pool and directly in front of your Threepeaters.

A simpler strategy is to fill as many places up with Starfruit as possible, as (just like Threepeaters) their projectiles go into other lanes. With a lot of Starfruit, you don't even have to worry about your pool lanes.

Another way to get the achievement is to play Big Trouble Little Zombie, without using the Lily Pads. All you have to do in this level is to make the simple setup, but not putting anything in the pool. The only way to kill the Ducky Tube Zombies and the Snorkel Zombies is to use the Cherry Bombs at the lanes that are the closest to the pool. So you should save the Cherry Bombs for emergencies at land, but mostly near the pool, to kill the Ducky Tube Zombies.

Last Stand Strategy: The Gloomwalk
Pick the following: Lay out as the following: Key: K=Kernel-pult GS=Gloom-shroom G=Garlic T=Tall-nut S=Spikeweed
 * Coffee Bean
 * Fume-shroom
 * Gloom-shroom
 * Garlic
 * Kernel-pult
 * Spikeweed
 * Tall-nut (Optional, but recommended)
 * Imitater Garlic (Optional)
 * Magnet-shroom (Optional)
 * Any other slot fillers

Remember to replace the Garlics after they get eaten. On the setup, you can replace the third Garlic with a Magnet-shroom.

Note: Completing a Fog level without using any aquatic plants will not count towards this achievement.

Trivia

 * The name of this achievement is based off the meme "Pool's Closed".
 * There is an equivalent achievement in the Nintendo DS version called "Don't Drink the Water".
 * It is impossible to get this when there are Snorkel Zombies if you don't use Instant Kills, Melon-pults or Gloom-shrooms.
 * The picture looks like a Zombie drowning.
 * Or it could be a Zombie rising from the Pool, instead of a Grave.
 * Pool's Closed, Sol Invictus, Don't Pea in the Pool, Don't Drink the Water, Hammer Time!, and The Stuff of Legends are the only achievements that are achieved in the Pool levels.