DIY project

How to build a DIY aquarium LED light

Advanced (electronics)8 steps$180

What you'll need

LED chips (CREE or Cree XLamp - mix 6500K white + Royal Blue 450nm + UV 400nm for reef)
LED driver (MeanWell HLG series)
Aluminum heatsink (3-5mm thick, sized 1.5x LED area)
Thermal paste
Optics/lenses (90° + 60° beam angles)
Hood enclosure (DIY plywood or aluminum)
AC power cord + plug
Soldering iron + solder
18-22 AWG wire

Step-by-step

Step 1: Plan the LED layoutFor reef: 60% Royal Blue (445-455nm) + 30% white (6500K) + 10% UV (380-410nm). For planted: 70% white (6500K) + 20% red (660nm) + 10% blue. Total wattage: 1-3W per gallon.

Step 2: Mount LEDs to heatsinkApply thermal paste to LED back. Press LED onto aluminum heatsink. Spaced 1-2 inches apart to allow heat dissipation.

Step 3: Solder LED wires in series + parallelWire LEDs in strings (series) matched to your driver voltage. Multiple strings in parallel. Watch polarity - LEDs are diode-directional.

Step 4: Connect driverDriver output connects to LED string + (positive) and - (negative). Driver input (AC) connects to wall plug. Use a fused power cord for safety.

Step 5: Add opticsSnap-on optics focus light. 60° for direct overhead penetration; 90° for wider tank coverage. Mix beam angles across the fixture.

Step 6: Mount in hoodBuild a plywood or aluminum hood that hangs over tank. Heatsink screws into hood interior. Optics + LED face down toward water.

Step 7: Test + tune intensityPower on at 30%. Use PAR meter (Apogee MQ-510) to measure at substrate level. Target: 100-200 PAR for LPS, 250-500 PAR for SPS, 50-150 PAR for soft coral.

Step 8: Add programmable controller (optional)Inkbird ITC-308 or Apex controller dims/ramps LEDs across the day. Sunrise + sunset cycles + storm modes. $30-200 for controller.

FAQ

Is DIY LED cheaper than commercial?

Yes for large tanks (48"+). DIY for a 6-foot tank: $150-300. Commercial Radion XR30 G6 array: $1,500+. For nano + standard tanks under 48", commercial is competitive.

What spectrum is best for reef?

Royal blue (445-455nm) is the dominant wavelength. Add some UV (400nm) for fluorescence. White (6500K) for visibility. Skip warm whites (3000K) - bad for coral.

Do I need a controller?

For DIY: yes - ramping prevents shock. Inkbird ITC-308 works as a basic dim controller for $30. Apex aquarium controllers integrate with the rest of your reef setup.

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Aquarium-keeping fundamentals

Whatever specific topic brought you here, four fundamentals govern long-term aquarium success: water quality, parameter stability, biological filtration, and species-appropriate husbandry. Skip any one and the others struggle to compensate.

Water quality: ammonia + nitrite at zero, nitrate under 30 ppm freshwater + 10 ppm reef. Test weekly with API or Salifert kits. Use our water parameter checker to score your readings against your tank type.

Parameter stability: stable wrong parameters beat fluctuating ideal parameters. Most fish tolerate a wide pH range if it's stable. Sudden swings of 0.4+ pH or 5+°F kill fish faster than chronic suboptimal values. Use temperature controllers (Inkbird) + automated dosing for consistency.

Biological filtration: the bacterial colony on your filter media + rock + substrate is the engine. Never replace all media at once. Use our filter turnover calculator to size correctly.

Species-appropriate husbandry: research adult size, territoriality, diet, and tankmate compatibility before purchase. Use our tank stocking calculator + compatibility guides.

Frequently asked questions

How long does an aquarium take to set up? 4-6 weeks for full cycling + first stocking. Use our cycle ETA calculator + how long does cycling take.

What's the best aquarium for beginners? 20-gallon long. Big enough for parameter stability, small enough for budget + space. See beginner picks.

How often should I do water changes? 25-30% weekly. See water change frequency Q&A + water change calculator.

Why does my fish keep dying? 5 leading causes: uncycled tank, wrong species pairings, no quarantine, undersized tank, neglected water-change schedule. See full diagnosis.