Quick Answer: Phytoplankton feeds filter feeders and LPS corals, Reef Roids targets SPS and mixed reefs with rapid growth, and amino acids support coral metabolism during stress. Most tanks only need one supplement — phytoplankton for softies/LPS, Reef Roids for SPS-dominant systems.
After 14 years of reef keeping and running a coral frag business, I've tested every coral food and supplement that promises magical growth. The supplement aisle at the fish store looks like a pharmacy, each bottle claiming to unlock your corals' potential. But here's what I've learned: most tanks need zero supplements, and the ones that do benefit only need one or two specific products.
The key is understanding what each supplement actually does biologically, which corals respond, and when you're just pouring expensive water into your tank.
Understanding What Each Supplement Actually Does
Phytoplankton: Living Food for Filter Feeders
Phytoplankton represents the foundation of the marine food web — microscopic algae that range from 2-200 microns. When you dose live or preserved phytoplankton, you're feeding organisms that capture particles from the water column.
I've found that Reef Nutrition PhycoPure and AlgaGen PhycoPure work best because they contain multiple species: Nannochloropsis (2-4 microns) for the smallest polyps, Tetraselmis (10-15 microns) for medium feeders, and Thalassiosira (20-30 microns) for larger filter feeders.
The biological mechanism is straightforward: corals with small polyps and high polyp density (like Goniopora, Alveopora, and most soft corals) evolved to capture phytoplankton. When you add it to your tank, these corals extend feeding tentacles and actively capture the cells.
But here's the non-obvious part: phytoplankton dosing only works if your tank has adequate bacterial populations to process the waste. I learned this the hard way when my nitrates spiked to 40ppm after aggressive phytoplankton dosing in a sterile, over-skimmed system.
Reef Roids: Concentrated Zooplankton Substitute
Reef Roids contains dried zooplankton, marine proteins, and fatty acids designed to mimic the natural diet of SPS corals. The particle size ranges from 150-600 microns, perfect for Acropora, Montipora, and other small-polyp stony corals.
What makes Reef Roids different from other coral foods is the protein concentration — around 60% crude protein versus 20-30% in most alternatives. I've measured significantly faster growth rates in SPS frags when using Reef Roids compared to liquid feeds or DIY preparations.
The feeding response is immediate and visible. Within minutes of dosing, SPS polyps extend fully, and you can see them capturing particles. This visual feedback makes it easy to determine if your corals are actually benefiting.
However, Reef Roids requires perfect timing. Dose during peak flow periods, and the food gets exported before corals can capture it. Dose during low flow, and it settles on rockwork, creating nutrient hotspots.
Amino Acids: Metabolic Support, Not Food
Amino acids work differently than particulate foods. Products like Red Sea Reef Energy AB+ and Brightwell Aquatics Aminio contain dissolved organic compounds that corals absorb directly through their tissues.
The mechanism involves facilitated diffusion — corals actively transport amino acids across their cell membranes to support protein synthesis and metabolic processes. This is particularly important during stress periods: bleaching events, shipping, fragging, or parameter swings.
I've noticed the biggest amino acid response in recently imported or fragged corals. Color returns faster, polyp extension improves, and survival rates increase. But established, healthy corals in stable systems show minimal response to amino acid supplementation.
The key insight: amino acids support coral health but don't directly fuel growth like particulate foods do.
Which Corals Actually Respond to Each Supplement
Phytoplankton Responders
Soft corals show the most dramatic response to phytoplankton dosing. Xenia, leather corals (Sarcophyton, Lobophytum), and tree corals pump visibly harder and grow faster with regular phytoplankton feeds.
Large polyp stony (LPS) corals with high polyp density benefit significantly. Goniopora, Alveopora, Duncan corals, and Tubastrea respond well to live phytoplankton. I've maintained Goniopora colonies for over five years using twice-weekly phytoplankton feeds — something I couldn't achieve without supplemental feeding.
Non-photosynthetic corals require phytoplankton to survive. Sun polyps, orange cup corals, and Dendrophyllia need regular phytoplankton feeds or they slowly starve.
SPS corals show minimal response to phytoplankton because their polyps are too small to efficiently capture most phytoplankton species.
Reef Roids Success Stories
SPS corals respond dramatically to Reef Roids. Acropora, Montipora, Pocillopora, and Stylophora show increased polyp extension, better coloration, and measurably faster growth. I've documented 2-3x faster growth rates in SPS frags with regular Reef Roids feeding.
Mixed reef systems benefit when the tank contains significant SPS populations. The key is having enough SPS biomass to consume the food before it degrades water quality.
Euphyllia species (Frogspawn, Hammer, Torch) capture Reef Roids particles effectively, though they also respond well to larger foods like mysis shrimp.
Most soft corals ignore Reef Roids entirely — the particles are too large for their feeding mechanisms.
Amino Acid Applications
Newly imported corals benefit most from amino acid supplementation. I dose Red Sea Reef Energy AB+ for the first month after receiving new shipments, particularly with SPS and challenging LPS species.
Stressed corals showing tissue recession, color loss, or poor polyp extension respond well to amino acids combined with stable parameters.
Recovery protocols after parameter swings, equipment failures, or disease treatment should include amino acids to support tissue regeneration.
Healthy, established corals in stable systems show minimal response to amino acids. This is where many reefers waste money — dosing amino acids in thriving tanks provides no measurable benefit.
When Supplements Become Expensive Water
The Skimmer Test
If your protein skimmer removes supplements within hours of dosing, you're wasting money. I've tested this extensively: dosing phytoplankton in an over-skimmed system results in dark, smelly skimmate within 2-3 hours and zero coral response.
The solution involves timing: dose supplements when skimming is reduced or temporarily shut off, allowing corals time to consume the food before export.
Nutrient Export Balance
Tanks with aggressive nutrient export (oversized skimmers, heavy carbon use, frequent water changes) often can't maintain sufficient dissolved organics for supplements to be effective. I've seen this pattern repeatedly: reefers dose expensive supplements while simultaneously removing them through excessive filtration.
The sweet spot involves moderate skimming, minimal carbon use, and allowing some organic buildup to support coral feeding.
Tank Maturity Matters
New tanks (under six months) rarely benefit from supplements because bacterial populations haven't stabilized. Dosing supplements in immature systems often triggers algae blooms or bacterial blooms instead of coral growth.
Mature tanks (18+ months) with established microfauna populations utilize supplements most efficiently.
Dosing Protocols That Actually Work
Phytoplankton Dosing Schedule
Frequency: 2-3 times per week for tanks with significant filter feeder populations. Daily dosing for non-photosynthetic coral systems.
Amount: Start with manufacturer recommendations, then adjust based on coral response and water quality. I use 5ml per 50 gallons of Reef Nutrition PhycoPure as a starting point.
Timing: Dose during moderate flow periods, 1-2 hours after lights-on when corals are actively feeding.
Skimmer management: Reduce skimming for 4-6 hours after dosing, or dose before scheduled skimmer cleaning.
Reef Roids Protocol
Frequency: 2-3 times per week maximum. More frequent dosing overwhelms most tank's biological filtration.
Preparation: Mix 1/8 teaspoon per 50 gallons with tank water until dissolved. Strain through fine mesh to remove clumps.
Flow timing: Dose during medium flow periods — enough circulation to distribute food but not so much that it gets immediately exported.
Target feeding: Use a turkey baster to direct food toward SPS colonies for maximum efficiency.
Amino Acid Supplementation
Stress protocols: Dose daily for 2-4 weeks during coral acclimation, recovery, or environmental stress.
Maintenance dosing: 2-3 times per week for established tanks with high coral loads.
Concentration: Follow manufacturer guidelines precisely — overdosing amino acids can promote bacterial growth and water quality issues.
The Economics of Coral Supplements
After calculating costs over multiple years, here's what I've found:
Phytoplankton: $15-20 per month for a 50-gallon mixed reef with moderate filter feeder populations. Cost-effective for appropriate tank types.
Reef Roids: $25-30 per month for regular dosing in SPS-dominant systems. Expensive but justified by measurable growth improvements.
Amino acids: $20-40 per month depending on product choice. Only cost-effective during stress periods or coral acclimation.
Most tanks need zero supplements if properly stocked with appropriate fish loads and fed quality foods. The fish waste and uneaten food provide sufficient nutrients for coral growth in balanced systems.
Making the Right Choice for Your Tank
Choose phytoplankton if your tank contains:
- Significant soft coral populations
- LPS corals with small polyps (Goniopora, Alveopora)
- Non-photosynthetic corals
- Clams, feather dusters, or other filter feeders
Choose Reef Roids if your tank is:
- SPS-dominated with Acropora, Montipora, Pocillopora
- A mixed reef with 50%+ SPS coverage
- Focused on maximum growth rates for fragging
Choose amino acids for:
- New coral acclimation periods
- Recovery from stress events
- Challenging species with poor survival rates
Choose nothing if your tank:
- Has heavy fish loads providing natural nutrients
- Shows excellent coral growth without supplements
- Struggles with algae or water quality issues
The supplement industry thrives on the idea that more is better, but reef keeping success comes from understanding your specific coral populations and feeding them appropriately — not dosing everything available.
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Frequently Asked Questions
- No, healthy corals in balanced systems with adequate fish feeding rarely need supplements. Only add supplements if you notice poor growth, color, or feeding response in specific coral types.
- Yes, but start with one supplement at a time to monitor coral response and water quality impacts. Combining phytoplankton and amino acids works well, but avoid overdosing any single supplement type.
- Phytoplankton and Reef Roids show immediate feeding responses within minutes to hours. Growth improvements become visible after 2-4 weeks of consistent dosing. Amino acids show stress recovery benefits within days to weeks.
- Reduce skimming intensity or turn off for 2-4 hours after dosing to allow corals time to consume supplements before export. Resume normal skimming to maintain water quality.
- Overdosing or inadequate biological filtration causes nutrient spikes. Reduce dosing amounts, ensure adequate bacterial populations, and maintain proper skimming to process supplement waste products.
- Commercial products offer convenience and consistent quality, but DIY phytoplankton cultures and homemade coral foods work equally well. Factor in time, effort, and success rates when comparing costs.
- Yes, soft corals respond best to phytoplankton and dissolved organics, while SPS corals prefer particulate foods like Reef Roids. Match supplement choice to your dominant coral types for best results.