Regrow Farming/Bloons TD

Please read the entire article BEFORE attempting to regen farm!

Regrow (or Regen) Farming is a method of gaining money, with high risk but very high return. It is based on using Regrow Bloons to infinitely duplicate bloons, and can only be performed directly in Bloons TD 5 Deluxe, Bloons TD 5 Mobile, and Bloons Monkey City (as of 2017) and Bloons TD 5 Steam. 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. Regen Farms must be started on Round 42. Beginner Maps are good maps to do it. The Basic Principle: When a Rainbow regenerating bloon is popped, two Zebra bloons will come out and regenerate back to Rainbows, and those two Rainbows if popped they will four Zebra bloons will come out. Repeat this and the bloons will multiply very quickly and stall the round so abilities can provide cash.

Advantages

 * This type of money farming can quickly gain huge sums of cash, if used well.
 * By Regen Farming successfully, experience points can be gathered very quickly. This is especially true if Rainbow Regen Rushes are looped over and over again.
 * It gives scope for other types of money farming, including Heli Farming and Supply Drop Farming.
 * Helps with Experience Point Farming of Ranks and Tower XP.

Disadvantages

 * The swarm may overwhelm the defenses if the Regen Farm does not go well. This is very common for inexperienced players.
 * The game may lag a bit on slower devices, especially if the Regen Farm is successfully done. In extreme cases, it may cause the game to crash.

Methods (Mobile/Steam or Deluxe only)
Remember, you can follow the strategy below or refer to the videos under this!

Preparing to Regen Farm
For beginners, you can practice this in Monkey Lane. An easy way to prepare for a regen farm is to start off with a 1/0 Engineer Monkey, then spending the next 22 rounds building 7-9 Banana Farms, getting most to at least 3-0. Upgrade to a 1/1 Engineer when cash is available or if you have 1 or 2 Banana Farms. When starting to lose lives or have difficulty, you should also get an Apprentice Monkey. Upgrade it to about 2/2, and to 2/3 when you have more difficulties. From then on, keep working on your Banana Farms until right before round 42. Before starting round 42, sell everything then begin one of the strategies below.

Actually Regen Farming
'''Remember, if you farm on round 42, beware, as camo rainbows also come with their regen counterparts. Pop these with mass amounts of road spikes, put at the end.'''

One method is to use about 3 or 4 3/0 Monkey Apprentices or 1 4/2 Monkey Apprentice with the Summon Whirlwind upgrade. Remember to start with one, so not to be overwhelmed. The tornado from the Monkey Apprentices will blow bloons back to the start, and by the time the bloons come back to the Apprentices, they will have multiplied. Get Sun Gods, Ring of Fires or any other strong towers to pop the regen bloons. Ray of Dooms work, but you must be careful not to aim them at the regenerating bloons or you will end your farm. Put your bloon poppers near the trees on the right side of Monkey Lane (if you're playing on this map), or around where the Ring of Fires are in the below picture. For Sun Gods/Super Monkeys, don't get range upgrades and refer to the picture on the right. Use 3-1 or 3-0 Monkey Villages to increase money gain, but be careful, these also increase range!

A cheap (and controllable!!!) way of regen farming is to utilize the ability for the Dartling Gun to change direction. Since Dartling Gun can also hit camo, this can also be used on camo rounds (or straight-out camo regen farming). you will need AT LEAST one Laser Cannon (for popping bloons), one 0-1 Dartling Gun (to regulate bloon flow), one 3-0 (or 3-2) Monkey Apprentice for blowback.

Some might say that a single 3-x Monkey Apprentice doesn't generate enough cash, but when you are low on defense don't ask for much. Wait for the Monkey Apprentice to blow back bloons. There shouldn't be a lot of regen bloons immediately, so for the first few seconds there is no need to "regulate" farming rate by popping bloons in the re-grow area. Try to maintain so there is less than 5 visible rainbows and about 20 zebras. That would be roughly what a single Laser Cannon can hold. ''Less is more. The less the regrow, the less the risk, but keep at least three regen zebra alive to not stop the farm.'' As you slowly ramp up on cash, build more 3-x Dartling Guns. When you have 10 Laser Cannons, stop stop regulating bloon regen. The bloons should be able to be held in line, but upgrade the defense a bit more (such as Ring(s) of Fire, Reactor, Bloon Dissolver).

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, although Rounds 42, 49, 51, 56, 62, 69, 72 and 76 is best. Regen Farming can lag and crash the game on Round 79 and 82. Since regrow farming is patched on BTD5, a good alternative is to stall the round with regen farming and spam 0/4 Sniper abilities to get cash. One way to regen farm uses 1 3-x Monkey Apprentice 1 3-x Ice Tower and 1 4-x Boomerang Tower. This strategy has infinite bloon popping power and you should not have to worry about losing lives. This in total costs 18290 on easy, 21560 on medium, and 23275 on hard. It's been found this to be cheap compared to most strategies to the other methods that have infinite bloon popping power. Put the Glaive Lord so that the blade will hit the bloons on the track and the Arctic Wind ability near it so that it will slow the bloons and give the Glaive Lord more time to pop the bloons. It is recommended that you get the 3/X monkey village as it increases the amount of money you get by 50%. First off set up the 3/X Monkey Apprentice near the back. Once you have enough money switch your popping power to a Ray of Doom which will pop the bloons quicker and reduce lag on your device. It is also recommended that you upgrade or buy another Monkey Apprentice. Another strategy is the Blizzard Reactor ROD strategy, which has so far worked on Slalom, Ice Flow, and other various water maps on BTD5 Mobile. This will work on Easy, Medium, Hard, and even Impoppable by buying and selling Farms. This can be achieved on Fast Track as well. First, place a 3-x Apprentice close to the "grind zone," further down the track but not behind the "grind zone". (The grind zone is the location where the cash building happens.) Placing the 4-x Monkey Sub near a considerably long section of the track - as in about one RBS - submerge for grinding power. Have a nearby 3-x Ice Monkey (This is to help reduce lag) with overlapping areas with the Reactor. Be warned: Camos do not get affected by the Ice Monkey's Arctic Wind upgrade, meaning it can be a major problem on Impoppable. The best rounds to put this into effect are rounds 42, 49, and 51. If you have the Tier three Dart Monkey Specialty Building, place the free unupgraded Dart Monkeys along the beginning of the track, but not in a cluster as this can stunt the rush. As the rush starts up successfully, place an unupgraded Bloonchipper between the Dart Monkeys and the Apprentice and set to strong. This can later be upgraded to increase regrow cash. Once the cash has begun to build up, upgrade the Apprentice to 4-x and set to last. As cash flow increases, create a 4/2 Dartling Gunner and place along track near grind zone and place at your choosing. Then let the game alone in the charger for hours at a time and watch your XP go through the roof!

Useful Towers for Regen Farming
'''Remember, only a few types of the towers listed below should be used. It is better to use only a couple types, instead of spamming one of each. Also, Movement reducers are recommended, but not at all needed. Towers in the other category may help but are also not at all needed.'''

Blowers:


 * Summon Whirlwind: Good for blowing bloons back, use 3 or more.
 * Tempest Tornado: Like Summon Whirlwind, blows much more. Use only 1 because the tempest tornadoes also pop the bloons as they blow them back. Although useful, make sure to have a VERY strong defense before using Tempest Tornados, as they multiply bloons EXTREMELY quickly!
 * Distraction: Recommended to get Bloonjitsu, so it blows more bloons. Although usable, this is unrecommended, and make sure you are very good at regen farming before using.Regen Farming with Downdraft.png
 * Downdraft (Mobile and Steam only): Blows the bloons below the Tower. It can be further upgraded to Support Chinook to further increase the income, as its ability gives money. Using Support Chinook over and over again while stalling the round is called Heli Farming.

Bloon Poppers:

These are some examples, but any tower with powerful popping power is good.
 * Ray of Doom: Very good for popping the regen bloons. The Dartling Ammo Dump makes it more effective and reliable, so you can lock on to one target, like the Mortar. This means you can't accidentally swipe, killing all the regen bloons and ending the farm prematurely. Also pops camo so you can regen farm on Regen Camo rounds. A good tower to use to reduce the lag in the game.
 * 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, although it won't do too much damage. 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. Be careful about its range.
 * Ring of Fire: 4-5 of these can destroy the Regen bloons so they don't leak.
 * Spiked Mines: 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. If something in your farm goes haywire, this can save your lives. May be good to use more than one, as if things are too bad, the bloons may still overwhelm the Spike Factory.
 * Glaive Lord: The Infinite popcap makes it pretty good since the Regen Rushes are very, very dense. Makes a good pair with Arctic Wind.
 * Bloontonium Reactor (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 completely, so using a Monkey Intelligence Bureau is usually not required.
 * Dragon's Breath: A large group of these can handle a rush of Regen Rainbows with the help of Robo Monkeys.
 * Bloon Liquefier: A group of these can disintegrate bloons very quickly. However, they still need backup from other poppers.
 * Blade Maelstrom: Spamming the ability can be a last minute safeguard from leaking bloons.
 * Triple Darts: Spamming these towers with a maxed Dart Training Facility and next to a Monkey Intelligence Bureau can rapidly liquefy many layers of bloons. Super Monkey Fan Club can also be used for desperate situations or simply to pop bloons faster. Be careful about its range.

Movement Reducers:

'''These give the bloons more time to regenerate, usually by slowing them down. However, too many of them can quickly cause the bloons to multipy too rapidly and overrun your defense, or even your computer.'''


 * 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 that enter the map 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. However, its slow does stack with Glue Striker.

Other:


 * Supply Drop Ability: Not useful for Regen Farming, but can give you additional money since the round can last for as long as you want. Using the Supply Drop Ability over and over again is called Supply Drop Farming.
 * Ground Zero: This is good if you want to end the Regen Farming, as it will kill all the regen bloons with its ability.
 * 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 radius.
 * Monkey Engineer (Deluxe, Mobile, and BMC Flash only): Can be upgraded to Bloon Trap to further increase money income, although it may accidentally kill the farm. 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 if you have a weak defense. Bloon Liquefier and Bloon Dissolver 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 it hits 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, so it's a risk.

Bloons TD 6
Earning extra cash through Regrow Farming was made significantly harder in Bloons TD 6:

After the nerf in Version 28.0 that prevented income-generating abilities from working 3 minutes after the start of the round, infinite income generation from Regrow Farming was made essentially impossible.
 * As in BTD5 Flash, duplicated Regrow Bloons do not give extra cash when popped.
 * Cash-generating abilities such as Supply Drop, Jungle's Bounty, and Monkey-Nomics have all suffered numerous nerfs (including having to wait out their cooldowns completely before the first use and having a cap on the number of uses per round) that make it harder to turn a profit when performing stalling of any kind to spam these abilities.

Regrow Farming, besides making money via income-generating abilities, can be used for the following:
 * Accumulating Paragon pops

Trivia

 * In BTD5, Regrow Farming is the only way to get a Temple on Round 31 in a normal game. (Not counting premiums or the use of cheating)
 * You can Regen Farm with Black/White/Lead/Zebra/Rainbow/Ceramic Regen Bloons, although Rainbows are best.
 * This is most preferred with Rainbow Bloons because they take less damage to pop than Ceramics & spawn far more children than Zebras.
 * However, if you have multiple 4/x wizards and you use the bloons on round 69, then the ceramic layer will be popped very quickly, and cause mass regrow farming (be warned that you may find a laggy screen.)
 * It is impossible to do regen farming on a normal level in BTD5 with Black Bloons/White Bloons/Lead Bloons as such they never appear in the game (blacks and whites can from regen zebras, but not on their own, but regen leads never show up.)
 * In BTD6 it is possible with Black and Lead bloons, but not whites.
 * It may crash the player's game if there are more bloons than the device can handle.
 * 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 missiles to the nearest 100 bloons, with an explosion.
 * Regen Farming is also a great way to get Experience Points fairly quickly.
 * At present, Regen Farming is only possible from split Regrow Bloons.
 * Rings of fires with arctic winds will get overwhelmed by a tempest tornado regen farm very very quickly so this method is not advised.
 * Like in BTD5 Flash, Regen Farming does not earn extra cash in BTD6, altrough it is still possible to do Heli Farming or Supply Drop Farming. Take note that these methods are unreliable on C.H.I.M.P.S. because extra income is disabled.
 * In BTD5 Mobile, Deflation Mode doesn't have split bloons.