Acid Pool

"If no Bloons are nearby Alchemist can drench nearby track with acid."

- Bloons TD 6 description.

 is the 2nd upgrade of Path 3 (1st upgrade of Path 3 prior to Version 21.0) for the Alchemist in BTD6. It allows the Alchemist to create small, short-lived pools of corrosive acid near it to damage bloons when none are within its radius or if the Alchemist misses. Each Acid Pool can soak up to 5 bloons or last for 7 seconds before disappearing, whichever comes first.

It costs $380 on Easy, $450 on Medium, $485 on Hard and $540 on Impoppable.

Summary
Generally, Acid Pool can seem a bit weak, but the acid pools can be crosspathed with middle path to improve damage. While still fairly average, it is a cheap way to slightly improve your MOAB and Ceramic popping power. Due to its situational purpose, it tends to be left out besides going for Lead to Gold or its further upgrades as a way for adding extra popping support.

Tips

 * Once 5 bloons pass over a pool, it is used up and all bloons hit become soaked in acid, having a similar effect as if it was splashed manually, dealing a total of 3 damage, 1 damage from the initial hit plus 2 layers of damage over 4.0 seconds.
 * The pools cannot pop Camo Bloons if the Alchemist doesn't have camo detection.
 * There is a special Monkey Knowledge called "Acid Stability" that allows the pools to stay for 5 seconds longer, massively boosting its potential.
 * It is not recommended to use Acid Pools as a crosspath in extremely laggy situations such as Freeplay Mode. Although for Permanent Brew it's not much a problem, as Acid Pool is usually skipped anyways, it can be very tempting to add it to Unstable Concoction.

Trivia

 * This upgrade is also affected by Stronger Acid and will change its visual design from red to purple and have similar damage.
 * The acid pool is not affected by Larger Potions.
 * If an acid pool potion hits a Camo Bloon without Camo detection, it will splash where it hit. This can limit where acid pools are thrown and the acid pool can sometimes be partially off the track.