*Free Delivery on all orders over £20 - available for a limited time only, order today and save £££s - Secure payments, discreet packaging!

Incredible Street Light LED offer live now instore only! - Dont miss out!

For a limited time you can buy the yield busting Street light 680w LED for just £575.00 when you pay digitally instore!

In fact come and see us for incredible discounts on all our LEDs including the Maxibright Daylight range and the mind blowing new 2.9umol Lumatek Zeus 600w LED!!

View all our LEDS now!

FloraFlex Rockwool Drip Components

We're please to stock the FloraFlex range of drip irrigation products including FloraCaps, Stackers and the FloraClip drip line clips. Check them out today and help evenly distribute your nutrient supply whilst beating the dreaded algae problems associated with rockwool growing.

FloraFlex Rockwool Drip Components

The Best LED Lighting Available - Huge Stocks

View all LED Grow Lights
Maxibright Daylight 660w pro LEDMaxibright Daylight 660w pro LED
Maxibright Maxibright Daylight 660w pro LED
£779.95
In stock
Maxibright Daylight 300w Pro LED 2.5 u/molMaxibright Daylight 300w Pro LED 2.5 u/mol
Maxibright Maxibright Daylight 300w Pro LED 2.5 u/mol
£379.95
In stock
Dio-Tech 830w LEDDio-Tech 830w LED
ControLED Dio-Tech 830w LED
From £189.95
In stock
Sun King LED 630w - 2.7umolSun King LED 630w - 2.7umol
Not specified Sun King LED 630w - 2.7umol
£624.95
In stock
Maxibright Daylight 1030w Pro LEDMaxibright Daylight 1030w Pro LED
Maxibright Maxibright Daylight 1030w Pro LED
£1,349.95
In stock, 5 units
Street Light LED -680w 2.7umol PPFD 1750Street Light LED -680w 2.7umol PPFD 1750
Street Light Street Light LED -680w 2.7umol PPFD 1750
£699.95
In stock
Infrared Thermometer
Not specified Infrared Thermometer
£29.95
In stock, 11 units
Maxibright Daylight iLink Cable
Maxibright Maxibright Daylight iLink Cable
£12.50
In stock
Lumatek Zeus 1000w Xtreme PPFD LEDLumatek Zeus 1000w Xtreme PPFD LED
Lumatek Lumatek Zeus 1000w Xtreme PPFD LED
£1,549.95
Re-stocking soon
Maxibright Daylight Lighting ControllerMaxibright Daylight Lighting Controller
Maxibright Maxibright Daylight Lighting Controller
£274.95
In stock
Lumatek LED Daisy Chain Link Cable 5mtr
Lumatek Lumatek LED Daisy Chain Link Cable 5mtr
£10
In stock
Daylight LED 480w ProDaylight LED 480w Pro
Maxibright Daylight LED 480w Pro
£749.95
In stock

NEW!!! - Introducing the Grodan 'Big Mama' rockwool blocks

After waiting many years for these huge rockwool blocks we can finally announce they are here and available now! Hugely popular in the USA these blocks are ideal for growing plants to full maturity check them out today.

Get 'Big Mamas' today!

Lowest priced 630w LED tent kit just £749.95!!! - get yours today!

FOR LESS THAN £750 YOU CAN GET- 2.7umol 600w led tent kit with professional light hangers (not cheap chain and hooks) and for a limited time a free nutrient starter kit included! WhispAir extraction system and heavy duty timer included!

Sun King 630w LED tent kit

Hand water like a Boss!

Check out our new XL Hand Water Pro
Kits - hand watering has never been so
easy and effective, even on a large scale!
These kits are available in many sizes
from 6-36 XL pots!

Hand Water Pro Kits

Get growing on a budget!

Budget grow tent kits to get you growing for less than ever before, now including
free nutrient
starter packs

Grow for less £££ -click here!

Critical Drip Systems!

Our drip systems combine the
best products of a select few
irrigation suppliers to create a
versatile run to waste drip system
that can be used with a variety of
substrates.

Automate your irrigation now!

Propagation kits

starting seeds and cutting couldn't be easier with our complete propagation
kits and propagation
tent kits.

Check out our propagation kits here!

Increase quality and yield!

Here is our collection of our favourite flower enhancing additives, add quality density and
yield with these top shelf additives!

Improve your quality here!

Plant Nutrition

A selection of the best nutrients available for your plants

Take a look at our base nutrients here!

Grow like a pro with our Budbox Pro tent kits!

Top quality tent kits
featuring the awesome
Budbox Pro grow tents
and everything you
need for a full grow!

Grow Like a Pro!

Ultimate Control Minimum Work!

IWS flood and drain systems are easy to set up, easy to use and achieve some very impressive results. 3 styles of system are available to suit all budgets.

IWS Flood & Drain Systems

Quieten down your ventilation!

Noisy ventilation fans are a pain, check out our range of acoustic filtration kits and
quieten down your grow
room today!

Shhh! silence is golden....

Our collections

View all
Isomax Silenced Fan Filtration Kits
Isomax Silenced Fan Filtration Kits
300w Maxibright Pro LED Tent Kit (1mx1m)
LED Grow Tent Kits
Coco Media
Coco Media
Budbox Pro 2.4mx2.4m Tent Kit
Budbox Pro White Tent Kits
Canna Coco A&B
Base Nutrients
Propagation Grow Kits & Tent kits
Propagation Grow Kits & Tent kits
Carbon Filters
Carbon Filters

Our best sellers

Shop our most popular products for this season.

Learn more
Maxibright Daylight 660w pro LEDMaxibright Daylight 660w pro LED
Maxibright Maxibright Daylight 660w pro LED
£779.95
In stock
Ecothrive Coco Lite 70/30 Mix 50L - price includes heavy item surcharge - cheaper instoreEcothrive Coco Lite 70/30 Mix 50L - price includes heavy item surcharge - cheaper instore
Ecothrive Ecothrive Coco Lite 70/30 Mix 50L - price includes heavy item surcharge - cheaper instore
£17.95
In stock, 35 units
3kw Fan Heater
Lighthouse 3kw Fan Heater
£54.95
In stock, 9 units
Buddhas Tree Coco A & B
Buddha's Tree Buddhas Tree Coco A & B
From £13.95
In stock, 16 units
XL Pro LED Tent KitXL Pro LED Tent Kit
Maxibright XL Pro LED Tent Kit
£1,159.95
In stock
Budbox White XL Grow Tent KitBudbox White XL Grow Tent Kit
Budbox Budbox White XL Grow Tent Kit
£329.95
In stock

Blog posts

View all
Winter Growing: changes to your growing style during cold months

Winter Growing: changes to your growing style during cold months

Colin Wilson
Establishing and Transplanting Young Plants

Establishing and Transplanting Young Plants

Colin Wilson
Growing With Drip Irrigation

Growing With Drip Irrigation

Colin Wilson

Find us....

Critical Mass Systems Sheffield

Unit 4, Holbrook Enterprise Park,

Sheffield

S20 3GL

Monday, Tuesday, Wednesday & Friday: 9AM - 6PM

Thursday 9AM - 7PM (Late Night)
Saturday: 10AM - 5PM
Sunday: 11AM - 4PM

Get directions