400V High Frequency Grow Lights

Free delivery on qualifying UK mainland orders over £50

Traditional magnetic and digital ballasts run HID grow lights on 230V. Due to improved efficiency, the latest grow lights are manufactured using to run at 400V. Commonly, 400V grow light systems produce 10% more light for the same amount of electric used. You can use the increased light output to help you increase yields. Read our buyers guide below for more information on 400V grow light systems, and how to use them in your indoor garden.

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Buyer's Guide

400V High Frequency Grow Lights


400V grow lights are the latest in digital grow light technology.


400V grow lights use standard, UK, 230V mains electricity. The ballast upscales the 230V to 400V as it passes through, on the way to the 400V grow lamp. This allows as much as 10% more light to be produced for the same electrical input as traditional 230V grow light units.


Due to the specialist components, that operate at a higher frequency, there’s less wear on bulbs. This makes them last much longer and means they maintain a high output for a longer life span.


400V grow light fixtures can be single ended (SE) or double ended (DE). DE fixtures cannot be hung vertically. You should only hang DE units horizontally, above your plants. Depending on the grow light fixture you choose, you’ll need to replace the bulb with like for like. This is because DE bulbs cannot be used in SE fixtures and vice versa.


Garden tip: Take extreme care to check the bulb you are fitting to an SE grow light fixture. It is possible to accidentally install E40 230V bulbs to an E40 400V grow light fixture, which will explode if powered by the 400V ballast .


The initial cost of 400V units is much more expensive. Don’t let that put you off. 400v grow lights are cheaper to run and the components don’t need replacing as often, so you recuperate the additional cost over time and have improved yields.


400V systems have compatible controllers, which allows you to precisely dim them. Controllers also allow asynchronous day and night timings, and temperature controls of 100s of 400V grow light units at a time.


Professional growers use 400V grow light fixtures with Ceramic Metal Halide (CMH) light fixtures as a supplemental light. This is due to 400V HPS grow lamps providing an increased yield. Supplemental CMH grow lamps help to fill in gaps in the light spectrum. This works to increase the final quality, and providing you with the best of both worlds.