Distance from the light – so important

Distance your plants are from the light is critical.

With sodium bulbs, they can stress your plants very easily.

Start with fluorescent about 40″ from your cuttings or seedlings.

Once your plants are about 12″ high, they can take the strength of a 250W light.

However, NOT directly shinining onto them.

Instead position your light in the centre, and move your baby plants to the far corner.  Distance from bulb to floor should be 4 feet.

 Once they have grown to around 18-24″ and are looking thick in the stems, you can then move underneath the light.  Still make sure there is 3 feet of distance.  If the plants stretch you know they need to go closer to the light.

If you don’t follow these rules, you stunt your plant growth with stress and it shows up later down the line.

Black and white sheeting or mylar

 

The big debate – do I use mylar sheeting as above or plain B&W sheeting?

Although on paper, mylar is more reflective, B&W is also reflective to a degree.

I would anticipate 10-15% increase in illums with mylar.

But with this you have to weigh up some factors :

- cost of mylar versus B&W sheeting or just plain white walls

- mylar will give you a headache if you’re in the grow room too long

- do I really care about the lower flowers getting much light?

Personally, I think B&W sheeting is the most effective.  You best investment is maintaining your hydroponics system impeccably and changing your bulbs regular.