💡 How much light do plants need in hydroponics? Simply and without myths
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Light is just as important in hydroponics as water and nutrients.
Without the right light, plants do not grow, fade and stretch out.
With good light, on the other hand, they grow quickly, are compact and have a strong flavor.
Let's explain how much light plants really need , without complicated calculations and unnecessary theory.
🌞 Why light is key in hydroponics
Plants produce energy from light (photosynthesis).
In hydroponics, where they have ideal access to water and nutrients, light is often the only limiting factor .
When they have little of it:
the leaves are turning pale
plants are being pulled out
growth will slow down
When they have had enough:
grow compactly
they have strong stems
they smell and taste better
⏱️ How many hours of light per day?
In home hydroponics, there is a simple rule:
Herbs and salads: 12–14 hours a day
Fruit plants (tomatoes, chilies): 14–16 hours a day
More than 16 hours usually doesn't help — plants need "night" too.
💡 What type of light is best?
🔹 LED grow lights
A clear choice today.
low consumption
little heat
long life
spectrum adapted to plants
Most home hydroponic systems use LEDs.
🔹 Daylight from the window
Yes, it is possible — but it has limits.
works well in the summer
in winter it is usually not enough
depends on the window orientation
The ideal combination is a window + additional lighting .
📏 How far should the light be from the plants?
General recommendation:
5–10 cm for weaker LEDs
10–20 cm for stronger lights
If the leaves are pale and the plant is stretching out → the light is too far away.
If the leaves curl or turn brown → the light is too close.
🌱 Different plants, different needs
🌿 Herbs (basil, mint, parsley)
medium intensity
regular hours
hates extreme
🥬 Salads
rather shorter lighting
colder environment
a lot of leaf matter
🍅 Tomatoes and chili
a lot of light
longer day
stronger LED
❌ Common mistakes with light
too short lighting time
irregular mode (manually switching on/off)
the light is too far away
relying only on the window in winter
A timer is ideal — a cheap but essential tool.
📝 Summary
Light is the engine of hydroponics.
It doesn't have to be expensive or complicated — but it does have to be set up correctly.
Basic rules:
12–16 hours a day
LED light near plants
regular routine
adapt to plants
When the light works, hydroponics works.