Regrow Farming/Bloons TD

As of September 18th 2013, Regen Farming is no longer possible on BTD5. It can still be achieved on BTD5 Deluxe and BTD5 iOS.

An example of regen farming, done in sandbox.

Regen Farming was a method of gaining money, with high risk but high return. It is based on regenerating bloons and can only be done in Bloons TD 5 (formerly), Bloons TD 5 Deluxe, Bloons TD 5 Mobile, and Bloons Monkey City. It is based on the fact that if a regenerating bloon gains a layer it doesn't give any money when popped but if it spawns 2 bloons they will give you money when popped.

Ex: When a Rainbow regenerating bloon is popped, two Zebra regenerating bloons will come out and regenerate back to Rainbows, and those two Rainbows if popped they will four Zebra regenerating bloons will come out .

File:Very Simple Regen Farm

A simple regen farm

Method

One method is to use about 2 or 3 3/2 Monkey Apprentices with the Summon Whirlwind upgrade. The tornado from the Monkey Apprentices will blow bloons back to the start, and by the time the bloons come back the the Apprentices, they will have multiplied. This can also be done with the Tempest Tornado upgrade, but it is best to only use a single one for this, or otherwise the bloons will either get popped right away, or likely overwhelm the player's towers. Another method is to use an Ice Tower with the Arctic Wind upgrade and a Ninja Monkey with Distraction. The Arctic Wind will give time for the bloons to multiply and the Ninja Monkey will pop them and send them back to the Arctic Wind.The player can Regen Farm on rounds 31, 42, 49, 51, 56, 61, 62, 69, 72, 76, 79, and 82. Since regrow farming is patched on BTD5, a good alternative is to stall the round with regrow farming and spam 0/4 sniper abilities to get cash.

Useful Towers for Regen Farming

Blowers:

• Summon Whirlwind: Good for blowing bloons back, use 2 or more.
• Tempest Tornado: Like Summon Whirlwind, blows much more. Use only 1 because the tempest tornados also pop the bloons as they blow them back.
• Distraction: Recommended to get Bloonjitsu, so it blows more bloons.
• Downdraft (mobile only): Blows the bloons below the Tower. It can be further upgraded to Support Chinook to further increase the income.

Bloon Poppers:

• Ray of Doom: Best for popping the regen bloons. Specialty makes it more effective. Also pops camo so you can regen farm on Regen Camo Rounds.
• Sun God: Not as good as Ray of Doom as it has a much lower Popping Power and its shots can accidentally hit the Regen Bloons at the start, ending the Farming. It can be used as an early defense until the player can buy a Ray of Doom.
• Technological Terror: More powerful than Sun God when both of its beams are trained onto the same target, but not so good at Popping Power.
• Ring of Fire: Many of these can destroy the Regen bloons so they don't leak.
• Spiked Mines Factory: At least 4 or 5 of these at the exit can handle a continuous line of Rainbow Bloons, depending on the regeneration rate of bloons.
• Glaive Lord: The Infinite popcap makes it pretty good since the Regen Rushes are very, very dense. Makes a good pair with Arctic Wind.
• Bloonsday Device: You will need various of them, it costs a lot of Monkey Money, but it can be purchased if you have few in-game cash. It's prefered to use the ability from the end to the start.
• You can also have 5+ tempest tornadoes to blow back and pop bloons at the very end.
• Bloontonium Reactor (mobile) (Submerged): A cheaper choice over the Glaive Lord since it also has near-infinite popping power, through not that great on its own, Arctic Wind and this make a deadly duo on popping even Tempest Tornado dense regen farming.
• Ice Shards: 3 to 6 of these bunched in the same area can very easily destroy dense hordes of Regen Bloons, but causes extreme lag due to thousands of shards flying everywhere. Even though Regen Whites and Regen Zebras can not be frozen, the shards from other frozen bloons will still pop these completly, so using a Monkey Intelligence Bureau is usually not required.

Movement reducers:

• Glue Hose: Slows bloons so they have more time to regenerate. Glue Soak required.
• Glue Striker makes it even more effective, slowing down bloons to 30% of their normal move speed as opposed to 40% with the Glue Hose. It also has the ability to glue every bloon on screen, further increasing effectiveness.
• Arctic Wind: Same as Glue Hose, but only affects them in range. Permafrost makes it more effective. With the level 3 Ice Fortress or a Monkey Intelligence Bureau, it can even double as a bloon popper.
• Sabotage Supply Lines: Bloons will be slowed down into 50%, through not as good as Glue Striker's ability as it glues all bloons and slowed down to 30%, and it is temporary, but cheaper.

Other:

• Supply Drop Ability: Not useful for Regen Farming, but can give you additional money since the round will last for infinite.
• Ground Zero: Good if you want to end the Regen Farming.
• Banana Research Facility: Tempest Tornado and Ray of Doom cost a lot and you can't get them on early rounds without heavily farming. Sell all the farms before you regen farm.
• Monkey Town: Greatly increases the amount of money that the attacking towers get you & their efficiency against the eternally spawning bloons. It can be further upgraded to High Energy Beacon to decrease the ability recharge time of all buildings in its radious.
• 1-2 Super Monkey: Only used near the middle lines when a powerful defense is made for the regenerating bloons. Greatly increases the amount of bloons that get popped per second. It is a good idea to upgrade it to Plasma Blasts after enough bloons spawn from the regenerating bloons. Alternetivly, the player can place down a 0-3 Robo Monkey instead, or just not upgrade it at all.
• Bomb Tower: can put it on close to make bloons regrow more easily.  You can also do a 3-2 for this purpose.
• Monkey Engineer (Deluxe & mobile only): Can be upgraded to Bloon Trap to further increase money income. Best used in good sized amounts away from where the bloons are being popped.
• Corrosive Glue: The glue will pop regen bloons, which then regrow, and the glue pops them again, and so on. It might however get too much out of hand and you'll have a leak. Bloon Dissolver is not as good but if you want to do minor farming it is recommended. Bloon Liquefier is not good because it pops way too fast for the bloons to regrow unless you want it to stop the bloons from leaking.
• Blade Maelstrom: Actually can either be a cheap Regen Farming Booster or a cheap Regen Farming Ender, as its ability has infinite popping power.  If you only have one, it is actually a Regen Farming Booster, as unlike the Glaive Lord, it doesn't do FPS damage, and hit one layer of Bloon. So a very dense Rainbow Regen Rush can actually be boosted, through a medium-densed Rainbow Regen Rush can actually be eliminated, depending on your Bloon Blowers.

Trivia

• It is the only way of getting a Temple of the Monkey God on the sockets of power on The Crucible (Not counting premiums and the use of Cheat Engine).
  • It is also the only way of getting a Temple on Round 31. (Not counting these)
• You can Regen Farm with Black/White/Lead/Zebra/Rainbow/Ceramic Regen Bloons.
  • This is most preferred with Rainbow Bloons because they take less damage to pop then Ceramics & spawn far more children than Zebras.
• It may crash the player's game in Bloons Tower Defense 5 Mobile, if he/she takes too long on a Round.
• A Monkey Ace with Ground Zero can instantly get rid of all of the bloons on screen, thus ending the farm.  However, this may be needed to save you, so it's a good idea to have one ready in case you are about to be overrun.
  • Using a Super Monkey Storm also gets rid of all the bloons, but Ground Zero is the better option because it doesn't use monkey money. A Rocket Storm Ability or two may also work, as they fire missles to the nearest 100 bloons, with explosion.
• Regen Farming is also a great way to get Experience Points fairly quickly.