Dimlux 315 Watt CDM Lamp
  • Dimlux cdm lamps %28all%29
  • 187785 dimlux cdm lamp %283k agro%29
  • 187786 dimlux cdm lamp %283k flower%29
  • 187787 dimlux cdm lamp %284k veg%29

Dimlux 315 Watt CDM Lamp


Choose your Dimlux CDM Lamp:

Dimlux 4K CDM Lamp

£99.95 £99.95
Dimlux 315 Watt CDM Lamp
  • Dimlux cdm lamps %28all%29
  • 187785 dimlux cdm lamp %283k agro%29
  • 187786 dimlux cdm lamp %283k flower%29
  • 187787 dimlux cdm lamp %284k veg%29

Genuine Dimlux Replacement 315W CDM Lamps for Dimlux CDM Grow Lights

When the time comes to replace the lamp in your Dimlux CDM fixture, you need to use these genuine Dimlux branded lamps to maintain the warranty on your Dimlux CDM fixture. This is because Dimlux fixtures and lamps have been designed and optimised to work together. There are 3 types to choose from, each with a different tailored spectrum. Choose from the 4K (extra blue for veg or for finishing of the flowering/fruiting phase), 3K (red for flowering/fruiting), or 3K Agro which is described by Dimlux as "Full Spectrum with extra Red" for all-round use. All types of CDM (Ceramic Discharge Metal-Halide) lamps give off a brilliant white light but now you can choose the spectrum that you prefer. Please see below for the actual spectrum graphs.

  • Genuine Dimlux branded replacement CDM lamps
  • Maintain the warranty on your Dimlux CDM fixture
  • Choice of 3 slightly different spectrums, each tweaked to optimise your plants' stage of growth
  • All 3 types provide brilliant white light that plants love
  • Emit 1.9 micromols (µmol) per watt


1 x Genuine Dimlux 315W CDM lamp in your choice of spectrum. Available in 4K, 3K or 3K Agro

How the Dimlux 315W CDM lamp Works:

Dimlux 4K CDM Spectrum:

Dimlux 4K CDM Spectrum with McCree Curve

Dimlux 3K CDM Spectrum:

Dimlux 3K CDM Spectrum with McCree Curve

Dimlux 3K CDM Agro Spectrum:

Dimlux 3K Agro CDM with McCree Curve

The black line in the graph above represents the "McCree Curve", which gives a relative indication of how efficiently a plant uses the different colours in the light spectrum to photosynthesise with.

For more information about the above graph check out our blog

While all Dimlux CDM lamps put out light in all the parts of the PAR range, the 3 types each have a slightly different spectrum which can allow a grower to match the lamp they use with the stage of growth. As can be seen from the spectrum readings, proportionally speaking the 4K version contains the most amount of blue, the 3K version provides the most red, while the 3K Agro version is described as full spectrum with extra red.

Blue light encourages leafy growth and keeps internodes short. Red light encourages the greatest flowering/fruiting response. 

The question of which lamp is best for you comes down to the intended purpose:

4K - Best for the vegetative stage and/or very end of flowering/fruiting to enhance aromas and tastes.

3K - Biased toward the red part of the spectrum for increased yields during flowering/fruiting.

3K Agro - Full Spectrum with extra red. The best all-rounder.

How to Use the Dimlux 315W CDM Grow Lamp:

These lamps are intended for use with a Dimlux CDM grow light fixture because the Dimlux ballast has been designed to drive them optimally. To replace your CDM lamp, first ensure that the grow light has been switched off and allowed to cool for an adequate amount of time. Remove the old lamp by grasping it and giving it about a quarter turn anti-clockwise. The lamp can then be removed from the lamp-holder. Always use a clean cloth to hold the glass of the new one. This is because the oils on the skin of your hands (even if they have just been washed) can cause damage to the lamp when it is switched on and becomes hot. Note that the 2 pins on the base of the lamp have different size rings on the ends of the pins. Insert the base of the lamp into the lamp holder ensuring that the small ring enters the small hole in the base of the lamp-holder, and the large ring enters the the large hole in the base of the lamp-holder. Give the lamp about a quarter turn clockwise to lock it in place (until it turns no more). Your Dimlux grow light can now be switched on.

PLEASE NOTE: The Dimlux 315w CDM lamps need to be bedded in as follows: on first illumination the lamp needs to be run continuously for a minimum of 15 minutes. This will allow the metals within the lamp to fuse correctly.

If the above is not adhered to, lamp warranty claims will be void.

As with all lamps the light output they produce will decrease with use over time. One Stop Grow Shop recommends you replace your lamp regularly to maintain your garden efficiency.

Please see the link below for a copy of the Dimlux warranty.