For the building in BMC, see Bloontonium Generator.
Activate submerge using target option to detect camo, pop bloons, and reduce water tower cooldowns 15% (doesn't stack).
~ Description from BTD5 Mobile
Submerge to detect Camo, pop Bloons and reduce ability cooldowns of nearby water-based Monkeys by 15%.
~ Description from BTD6
Bloontonium Reactor is the fourth upgrade on path one for the Monkey Sub. It allows the sub to reveal Camo Bloons, in the same way as Submerge and Support, but when submerged, it will also pop bloons with its Camo Bloon revealer. As a bonus, it reduces water tower ability cooldowns (First Strike Capability and Monkey Pirates, as well as the new Pirate Lord ability in BTD6) by 15% if they are within its radius. It should be noted that while the cooldown bonus does not stack with other Bloontonium Reactors, it will still stack with High Energy Beacon and Hotter Cooldown (85% total if hotter cooldown is fully upgraded, or 65% total on BTD5 Flash with the premium upgrade). In BTD6, this upgrade also blocks Regrowth in its range.

Update History (BTD6)Edit


Buff Bloontonium Reactor pierce increased (30 → 70).

Update History (Bloons TD Battles Mobile)Edit


Nerf Bloontonium Reactor price increased ($2500 → $2800).


Buff Bloontonium Reactor now automatically switches the tower into submerged mode upon purchase.


Nerf Fixed a bug where Bloontonium Reactor's water tower cooldown decrease stacked with any other Reactor in range



  • In BTD5, this is one of the few upgrades that has infinite popping power.
    • In BTD6 it has been nerfed to only pop up to 30 bloons per pulse.
      • However, in version 2.0, the upgrade has been buffed to pop up to 70 bloons per pulse.
  • A submerged Bloontonium Reactor acts like a Ring of Fire, but it is used on water and it has Camo Bloon detection, as well as reducing the cooldown of nearby water towers.
  • In Bloons TD Battles, with a regular defense, it can stop a Rainbow Bloon rush.
  • In BTD5 Flash, multiple Bloontonium Reactors placed close to each other can stack their popping power, and 2 to 3 of them can stop even a full Regrow Ceramic if placed precisely.
    • In Mobile, Bloontonium Reactors popping power does not stack.
  • In BTD5 Mobile, the Bloontonium Reactor has sailplanes. On the web version, however, this is not true.
  • If you look closely, the boat looks like a Los Angeles class nuclear attack submarine.
  • It decreases the cooldown of nearby water tower abilities by 15%.
    • This unintentionally stacked with multiple subs, so you could heavily decrease cooldowns.
    • There is a glitch in BTD5 and BMC, where, if you upgraded to a Bloontonium Reactor and then upgrade the bottom two upgrades after, it further increases the cooldown by 15%. This could be used with multiple subs to stack cooldowns and make hypersonic abilities.
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