I see this happen all the time. A beginner buys a beautiful green plant, puts it in a tank with no light, and says: “My room is bright enough. The ceiling light is on.”
Three weeks later, the plant is melting, brown, and dead. Here is the hard truth: To a plant, your “bright room” is actually a dark cave.
1. The “Food” Analogy
Plants don’t just “like” light. They eat it.
- Fish eat pellets.
- Plants eat photons (light particles).
If you don’t give them a dedicated light source directly above the water, they starve. They will start consuming their own leaves to survive (which is why they turn yellow and get holes), and eventually, they melt away.
2. Mistake #1: “I’ll just put it near the window.”
This is the most dangerous mistake in Malaysia. Our sunlight is too powerful.
- The Result: If you put a glass box of water in direct sunlight, you aren’t growing plants. You are farming Algae.
- The Green Soup: Within 5 days, your water will turn green, or hair algae will cover everything.
- The Fix: Keep your tank away from the window. You want to control the light, not let the sun dictate it.
3. Mistake #2: “The Ceiling Light is Enough.”
Light loses power very fast as it travels. By the time the light from your ceiling bulb travels 2 meters down to your floor and punches through the water surface, it has lost 95% of its energy.
- The Fix: You need a light sitting on top of the tank. Even a cheap RM15 LED clip-on light is 10x better than a ceiling lamp.
4. How Much Light Do You Need? (The 2 Levels)
You don’t need a RM500 professional light for everything. It depends on what you bought.
Level A: The “Low Light” Plants (The Survivors)
- Plants: Anubias, Java Fern, Bucephalandra, Cryptocoryne.
- Light Need: Low.
- Gear: A cheap generic LED (white light) is fine. They grow slowly but won’t die.
- Duration: 6 to 8 hours a day.
Level B: The “High Light” Plants (The Divas)
- Plants: Red Plants (Rotala Blood Red), Carpeting Plants (Monte Carlo, Hairgrass).
- Light Need: High Intensity (RGB).
- Gear: You need a specialized “Full Spectrum” aquarium light (like Chihiros or Netlea). If you use a cheap light, red plants will turn green, and carpets will grow tall and stringy.
- Duration: 8 to 10 hours a day (plus CO2).
The “Shop Guy” Secret: The Siesta Method
In Malaysia, algae is a huge problem because it’s hot. To prevent algae while keeping plants happy, use a Timer to split your light schedule:
- ON: 8:00 AM – 12:00 PM (4 hours)
- OFF: 12:00 PM – 4:00 PM (4 hours “Siesta”)
- ON: 4:00 PM – 8:00 PM (4 hours)
Why? Plants can adapt to the break. Algae cannot. This “Siesta” weakens algae but keeps plants growing.
The Bottom Line
Yes, you need a light. Don’t rely on the window. Don’t rely on the ceiling. Go to Shopee or your LFS, spend RM20 on a simple clip-on LED, and plug it into a RM10 timer. Your plants will stop melting, and your fish will look better too.
