400W Grow Light Kits

Why a 400W HPS Kit is Still the King of the 1m² Tent

Let’s be real. In a world full of new tech, the **400W HPS (High Pressure Sodium)** setup remains the undisputed champion for many growers, especially if you are rocking a standard **100x100 cm grow tent**. Why? Because it hits that sweet spot between light intensity, penetration, and electricity consumption.

When you fire up a 400W lamp, you are delivering enough lumens to penetrate the canopy deeply, ensuring those lower buds get fat too, not just the top colas. It’s the classic recipe for hitting that 400-gram harvest mark if you play your cards right. Plus, compared to larger setups like the Kit 1000W grow light, the heat is much easier to manage without needing an industrial-grade extraction system.

Basic Magnetic Kits: Old School Power on a Budget

If you are just starting out or your wallet is a bit tight, don't sweat it. The classic **magnetic ballast kits** are robust, reliable, and get the job done. They might be a bit heavier and run slightly hotter than their digital cousins, but they have been growing award-winning weed for decades.

These kits usually come with an open reflector (like the stucco or smooth finish) that spreads the light evenly. It’s the most affordable way to jump into the world of HID lighting. Just plug it in, hang it up, and watch your plants explode in growth. It’s raw power, no frills, and perfect for learning the ropes of grow lights without breaking the bank.

Going Pro: Electronic Ballasts and Cooltubes

Now, if you want to treat your plants like royalty and save some cash on the electricity bill in the long run, you should look at our advanced options. Upgrading to **electronic ballasts** changes the game. They don't flicker, they run silent, and they extend the life of your bulbs significantly. Plus, many are dimmable, giving you total control over the intensity during different growth stages.

Struggling with high temperatures? That’s where the **Cooltube** comes in. By enclosing the bulb in a glass tube connected to your extractor, you suck the heat straight out before it warms up your tent. This allows you to bring the light closer to the plants without burning them, maximizing the lumen uptake. If you are serious about efficiency, check out our standalone electronic ballasts to customize your setup.

Tips to Keep Your Lumens High and Electricity Bill Low

Buying the kit is just step one. To get those sticky, dense flowers we all love, you need to maintain your gear. HPS bulbs degrade over time—even if they still light up, their spectrum and intensity drop after a few crops. Changing your bulb every 3-4 grows is a smart investment that pays for itself in yield weight.

Also, keep your reflector clean! A dusty reflector can steal up to 10% of your light. And remember, once you’ve nailed the growing part, the next challenge is preserving those terps. Make sure you have your harvesting and drying marijuana process dialed in so all that light energy doesn't go to waste.

Frequently Asked Questions About 400W Lighting Kits

What size grow tent is best for a 400W light?

A 400W kit is mathematically perfect for a **1m x 1m (1m²)** space. You can use it in a slightly smaller space (like 80x80cm) if you have good ventilation, or up to 1.2m x 1.2m, though the edges might get a bit less light intensity.

How far should I hang a 400W light from my plants?

Generally, you want to keep it about **30 to 40 cm (12-16 inches)** away from the canopy. If you are using a Cooltube, you can get closer. A simple trick: put your hand at the top of the plants; if it’s too hot for your hand, it’s too hot for your ladies.

Does a 400W HPS kit use a lot of electricity?

It consumes exactly what it says: 400 watts per hour (plus a little extra for the ballast inefficiency). It’s very manageable for a home grower and significantly cheaper to run than 600W or 1000W systems, making it a great balance for personal supply.

Can I use both MH and HPS bulbs with these kits?

Yes! Most modern ballasts (both magnetic and electronic) in these kits are compatible with both **Metal Halide (MH)** for the vegetative stage and **High Pressure Sodium (HPS)** for flowering. Just make sure you switch the bulb when you flip the photoperiod.