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Grow light for chaetomorpha

By Centridae4 min read
chaetogrow lightrefugium

This guide covers everything you need to know about grow light for chaetomorpha in a saltwater reef aquarium context. No freshwater content.

Overview

Grow light for chaetomorpha — practical guide for saltwater reef keepers. Lighting is one of the three pillars of a successful reef tank—alongside flow and chemistry. The right lighting supports photosynthesis in coral symbionts (zooxanthellae), drives coral coloration, and establishes the visual aesthetic of your aquarium. Getting it wrong leads to bleaching, browning, or algae problems.

Key takeaways

  • PAR (Photosynthetically Active Radiation) is the most meaningful measurement of light for corals. Aim for 50–100 PAR for soft corals, 100–250 for LPS, and 250–450+ for SPS.
  • Spectrum affects both coral fluorescence and growth. Blue-heavy spectrums (420–480 nm) enhance fluorescence, while full spectrum supports maximum PAR.
  • Photoperiod should be 8–12 hours per day. Ramp up over 30–60 minutes and ramp down similarly to simulate sunrise and sunset.
  • Consistency matters more than intensity. Keep your lighting schedule and intensity stable from day to day.

In practice

When selecting and configuring reef lighting, consider these practical factors:

  1. Tank depth. PAR drops dramatically with depth. A 24-inch tall tank needs significantly more powerful lights than an 18-inch tank to reach the same PAR at the bottom.
  2. Coral placement. You do not need uniform PAR across the entire tank. Create zones: high-light areas near the top for SPS, mid-light zones for LPS, and lower-light areas for mushrooms and soft corals.
  3. Heat output. LED fixtures produce less heat than T5 or metal halide but still add thermal energy. Factor this into your heating/cooling strategy.
  4. Coverage area. Ensure your light spread covers the full footprint of your tank. Use a PAR meter to check for dark spots, especially at corners and edges.

Common mistakes

  1. Too much light, too fast. New corals need time to adjust. Start at 50–70% intensity and ramp up over 2–4 weeks.
  2. Ignoring PAR. Fixture manufacturers advertise watts, lumens, and coverage area, but only PAR tells you what your corals actually receive. Borrow or buy a PAR meter.
  3. Placing SPS corals before measuring PAR. Putting an Acropora in a random spot without knowing the PAR at that location is a gamble that often fails.
  4. Running lights too long. More than 12 hours of photoperiod promotes algae growth without significantly benefiting corals. Stick to 8–10 hours for most reef tanks.

Tips for success

  1. Invest in or borrow a PAR meter (Apogee MQ-500 or similar) to map light zones in your tank.
  2. Start new lights at 50% intensity and increase by 10% per week until you reach your target PAR.
  3. Use a blue-heavy spectrum (70% blue, 30% white) for maximum coral fluorescence while maintaining growth.
  4. Mount lights at a consistent height and angle—adjusting height changes PAR at the coral significantly.
  5. Clean the light lens monthly. Salt creep and calcium buildup on the lens can reduce output by 20%+.

Frequently asked questions

LED or T5 for reef tanks?

LED fixtures dominate the modern reef hobby due to their efficiency, programmability, and spectrum control. T5 fixtures still excel at providing even, diffused light that is forgiving of coral placement. Many advanced reefers use LED-T5 hybrid setups for the best of both worlds.

What PAR do my corals need?

Soft corals: 50–100 PAR. LPS corals: 100–250 PAR. SPS corals: 250–450+ PAR. These are general guidelines—individual species vary. Always acclimate corals gradually to new lighting.

How long should my lights be on?

Run your main lights for 8–10 hours per day. Include 30–60 minute ramp-up (sunrise) and ramp-down (sunset) periods. Some reefers run a blue-only supplemental period before and after the main photoperiod for viewing.

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