Water Cooled LED Grow Light – 300 TRUE watts – Wifi/4G Enabled – Custom Made by whiteWIDOW SeedBank

(1 customer review)

$USD 258.31 $USD 222.03

  • CAD: $CAD 299.99

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Water Cooled LED Grow Light – 300 watts –  Custom Made by whiteWIDOW SeedBank + Wifi/4G Enabled!


300+ Watts of TRUE LIGHT POWER

  • Looking for a truly SILENT lighting solution for your home or apartment?
  • Want to greatly REDUCE grow box temperatures?  
  • Want to ELIMINATE plant stress from excessive heat?
  • Want to DOUBLE-TRIPLE the life of your CARBON FILTER?
  • Want to ELIMINATE the need for a humidifier or dehumidifier?
  • Want to GROW WITH CO2 and seal your room?



We couldn’t find the stealth lighting solution we wanted to lower temperatures in our grow room. So we decided to build our own!  After a few years of testing different designs producing EXCELLENT results, we’ve decided to offer these lights to our customers.  Our latest design allows you to easily DAISY CHAIN as many lights as you want. Plus, we’ve incorporated an ADJUSTABLE DIGITAL PROTECTION CIRCUIT to ensure the LEDs can never overheat.  Want remote 4G/Wifi monitoring and control? We can add a WIFI/4G DIGITAL TEMPERATURE SENSOR to control your lights with the free eWelink Android or Apple app.  



Heat is a byproduct of LEDs – no matter how efficient they are. ALL high power LEDs need to be cooled or they will burn up in a matter of minutes. A typical LED grow light has its LEDs attached to a large aluminum heatsink and high speed fans blow large volumes of air over the heatsink to keep it cool.  Just about every high power grow light works this way. The problem is that AIR is not an efficient medium to remove heat. Massive amounts are required to remove the heat from the aluminum. (Air has a thermal conductivity rating of just 0.0262 w/(mK)). This is why noisy high speed fans are required. The higher the power of the grow light, the more heat it generates, and the more heatsink area and air required to keep it cool. It is a vicious cycle!

An air cooled LED grow light is just like putting a heater in your grow box. You are circulating the SAME AIR that your plants are utilizing with extremely hot air produced by the LEDs. This dramatically raises the temperature of your grow area!  Plants like a comfortable 20-30C / 68F-86F temperature range. So your only option is to use a second high volume fan to pump/suck cool air into the box to remove all that heat your LEDs just generated! Considering that air has interacted with your plants, it now also needs to be filtered through activated carbon to remove its smell.

Quantum boards while extremely efficient, still require cooling. Their drivers make heat, and because the drivers are still in your grow tent, that heat now needs to be removed!



We use extremely economical, yet efficient, third generation COB LEDs and thermally bond them to a special hollow aluminum water block. By circulating cool water through this water block (with a almost silent water pump) nearly all the heat generated (90-95%) by the LEDs is instantly transferred to the water. This hot water is then routed to the OUTSIDE of the grow box (by small PVC water lines) and into a small heat exchanger (radiator).  This radiator then transfers the heat from the water back to the air (with the help of 4 low speed fans), then the cooled water is circulated back into the system. (A closed loop system!). The result is a nearly SILENT grow area, no excessive heat being generated in the grow box (stressing the plants), no high volume fans inside are required, and reduced wear and tear on your carbon filter! The savings in electricity and carbon filters alone can make up the cost of ownership!  Not to mention the peace-of-mind that comes with a nearly SILENT grow area!



One of the biggest benefits of removing all the excessive heat energy from a grow area (VIA water cooling) is that you can almost eliminate the use of annoying humidifiers and dehumidifiers.  Why?  Because with normal air cooled / quantum systems – you need huge volumes of air and high speed intake/exhaust fans to get rid of it. Unfortunately this also means you are removing water vapor as well, requiring the use of a humidifier to maintain your required humidity level.  It is a viscous, energy wasting cycle.

With water cooling you just need to find the equilibrium between radiator fan speed (which controls the water block temps and ultimately ambient air temps in the grow area) and your exhaust fan volume.

For example – lets say you want to increase the humidity in your grow area from 40% to 50%, but maintain the same 25C grow area temperature.  By lowering your exhaust fan speed you now allow your plants to saturate the air with more water vapor.  But because there is less air moving in/out of your tent, the water cooled lights will begin to heat the tent up more.  The easy solution is to make the lights run cooler by INCREASING the speed of the fans on the radiators.  Cooler water translates into a cooler grow area.  Even a small increase in rad fan speed will reduce the temperature by a few degrees!  (Our fans are controlled by variable voltage power supplies. Just turn a knob to control their speed from 5%-125%. ).

You definitely can not “control” the temp of your air cooled or quantum boards – like you can with water cooling!



  • Number of LEDs:  6 COB leds X 50-55 watts each  
  • Total power draw:  300-330 true watts @ 120v  
  • Type of LEDs:  3rd generation COBs with integrated driver on board
  • LED Spectrum options:  3500K, 6000K, Red-Blue 380-780nm, 455nm
  • Beam Angle:  120 degrees
  • Water requirements:  1 Gallon / 3.7 Liters per minute (recommended)
  • Recommended water temperature range: 5-50C / 68F-104F  (Lower water temps reduce grow area temps and increase water pump life)
  • Thermal protection: External adjustable thermal relay protection 
  • Dimensions: 10” X 3.5” X 3”    / 26cm X 9cm X 8cm  (TINY!)
  • Weight:  only 500 grams! 





How big of a grow space will one of these 300 watt water cooled LED grow lights accommodate?  

It is a standard industry recommendation to give your plants 50-75 watts per square foot.  So a single light will provide more than enough light to cover a 2X2’, 2X3’ grow area, possibly a 3X3’ area if the area is not jam packed full.   You can always go with less lights, but for maximum canopy penetration, yield, and flexibility, it’s always better to have more than less!  

If you aren’t sure how many you need/want – you can also just buy a few, set them up, and EASILY add more lights later.   Our whiteWIDOW team members personally run 50 watts per square foot during VEG cycle and 75 watts per square foot during FLOWERING cycles – with excellent results.


Can I get my lights made in 220-240v instead of 120v?

Yes, we can custom make the 220-240V grow lights for you.  There may be an extra shipping expense to get the 240v LEDs in if we do not have them in stock.  Please contact us for more information.


Why did you go with these specific LEDS?

We tested these LEDs over the past 1.5 years and found they perform very well.  We are also trying to keep the cost down! While there are much more efficient LEDS on the market (Like CREE COBs), they are exponentially more expensive!  This would mean a single 300 watt light bar will cost 3-4 times more money, due to the direct cost of the COBS, additional electronics (drivers), and fabrication considerations.  Instead of spending $500+ for a single light, you can dive right into water cooling with a minimal investment. The money saved on equipment would even allow you to DOUBLE/TRIPLE the amount of lights you can purchase within the same budget!.  More lights, more coverage. You get the idea.


Does this light come with the water reservoir, hoses, heat exchanger, pump, and fittings?

That is a separate kit.  Please look in the store for the MASTER COOLING KIT


I want to daisy chain multiple lights together for a larger grow space. How hard is it?

Hang the light, connect a PVC tube splitter (or parallel your lights/water lines) to direct water to your additional lights, and plug it in.  IT IS THAT SIMPLE! Once you have your pump, water lines, and radiator all setup, it’s only a bit extra work to add more lights to the system.  Literally about 10 minutes per light. That’s it! 


How many lights can I daisy chain?

Assuming you want your system as QUIET as possible, we recommend 4-5 light bars (max) per heat exchanger (radiator).  This is mainly because beyond 4-5 light bars the radiator fan’s speed needs to be significantly increased to properly cool the water.  This starts to become loud (in our opinion). If you add a second radiator (and its 4 fans), you effectively double the cooling capacity.  We have actually run 16 X 300 watt lights on a single PVC waterline, pump, and 4 radiators – FOR A TOTALLY SILENT GROW AREA! The only noise came from the exhaust fan, and small oscillating fans inside the area! 

However, If you are not worried about noise – you can crank these DELTA fans right up and get some serious air volume out of them!


How powerful is the pump?

We use really high quality brushless pumps.  The 12V version will easily give you about 4-5 meters of head height, more than enough to circulate water around a room with 4-8 lights, and with the radiators on the floor in another room.

If you need to pump water to another floor (basement to a main floor) or really long distances, we also offer a 24V version which provides 15 meters of head and twice the volume.  (Please inquire about 24V)

The pumps we provide in our kits have been tested by the whiteWIDOW team members for nearly 3 years of operation with ZERO failures.  We recommend keeping the water circulating 24/7, and all our pumps have been operating non-stop since the prototypes first went out!

All pumps come with variable voltage power supplies – to control their speed from 20-110%.


What are my LED options?

Each LED Light bar has 6 X 50w LEDS totaling 300 watts.  We highly recommend one of these 3 LED combinations:

  • A) 6X RED-BLUE 380-780nm LEDs  – (Specifically designed to provide mostly blue and red light spectrums)
  • B) 3X Red-Blue 380-780nm LEDS + 3X 3500K LEDS  (Easier to see plants, Provides far-red 700+nm,  and provides extra yellow/green spectrum – Our recommended combination)
  • C) 4X Red-Blue 380-780nm LEDS + 1X 3500K LED + 1 X 6000K LED

We have had excellent results from these combinations.  However, we can custom build the LED light bars from these 4 COB LED options to suit your application:

  • 3500K – Warm white light
  • 6000K – Cool white light
  • 380-780nm – RED-BLUE light only – Specifically designed for growing plants 
  • 455nm – Blue light only (only useful for veg period)


Do you have Light Spectrum maps for each kind of LED?

Yes – please see the graphics above!


Do these lights put out FAR-RED 700+nm light?  

Yes – The RED-BLUE LEDS have the necessary and recommend amount of far-red light.  Here is a recent video from Dr.Bruce Bugbee (Apogee Instruments) which explains why far-red is important and why we recommend the 4X RED-BLUE + 2X 3500K LEDS per light bar.


Do I need to buy LED Drivers and other power supplies?

No. Just plug the 2.5 foot power cord into any standard 120v AC wall outlet.  The drivers are built into the lights.


How long have you been testing this design?

We have had whiteWIDOW private and commercial customers around the World using these over the past 36 months. They all have been running 12-20 hours a day growing autoflowering and photoperiod plants. We have had ZERO problems.  The entire whiteWIDOW team also has been using them, and have had excellent results!  Shoot us a message and one of the team members can provide you with REAL WORLD usage feedback. 


How are these lights protected?

Each light comes with a digital protection circuit which constantly monitors the water-block temperature.  We program the circuit to shut the light off if it ever reaches more than 50C, ensuring no damage can ever occur. We’ve actually had customers accidentally kink water lines, water pumps that have accidentally been shut off, even had pets chew holes in water lines (that were not routed properly) and the protection circuit worked perfectly.  The protection circuit is fully adjustable from 0 -100C and takes only seconds to adjust. If a light ever overheated, once the light cools down, the light will automatically turn on.


How do I know what the temperature of the water is?

The digital protection circuit has a real time LED temperature display built in.  Alternatively you can have our Smart WIFI/4G sensor installed directly onto the waterblock to both control the light and see the temperature on the Android / Apple app.


Can I turn some of the lights off for different growing phases?

We opted to not bother installing light switches for each individual 50W LED.  We did this because we found it significantly increased the production cost of the light bar. We also found that if you require less light, you can either move the light up higher, or simply open the power/control box on top of the light bar and disconnect the LED’s power wire directly in about 30 seconds.  


Do you have any whiteWIDOW Seed Bank reviews we can read?

Check out our reviews on Facebook: 


I want to add a WIFI / 4G SMART Controller and temperature sensor so I can remotely control and monitor water temps. How does it work?  What is the cost?  

The smart box plugs into your 120v wall power outlet, and then the LED light bar plugs into it.  A special temperature sensor is epoxied onto the light bar – and then this plugs into the smart controller box. You then simply download the eWelink app and you can not remotely monitor the temperature of your water cooled lightbar, set operational temperature thresholds, and program on-off cycles (timer).  You can buy the smart controller here.  And we charge $20 CDN extra to install the sensor. 


If I purchase a group of lights – can I get a discount?

SURE!  We are happy to put together a package deal for you, especially if you would be willing to either review it on social media (Facebook / Instagram / Reddit), forums, or provide us with pictures of the install.



Please also take into consideration that these are NOT mass produced in some factory overseas. They are made locally mostly from off the shelf parts. While we are now on the 4rd generation (we are constantly upgrading parts and finding better ways to build them), each light will have subtle custom/hand made attributes. If you want something that is flashy or hyper perfect, please get a light off Amazon.  If you want something that custom made and services a unique purpose unlike anything else on the market – then please DO BUY. 



1 – Watercooled LED Grow Light (assembled)

1 – Adjustable protection circuit (assembled + pre-programmed to shut down lights at 50C+)

1 – 2 foot power cord (assembled onto power/safety controller)

2 – 8 foot adjustable hangers

2 – Free White Widow autoflowering or photoperiod seeds

1 – Basic diagram + instructions




Additional information

Weight 500 g

1 review for Water Cooled LED Grow Light – 300 TRUE watts – Wifi/4G Enabled – Custom Made by whiteWIDOW SeedBank

  1. GTA Growers (verified owner)

    The research that WW has put into these lights is really starting to show in the health of my plants like I have never seen before.. Pineapple Express and Rainbow Zkittlez Autos are going into flower in a couple weeks and these lights have kept plant growth at a very nice rate and very healthy, will update in flower, can’t wait. Great lights and my Temps are staying nice and low.

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