Phytoplankton Culture Setup
Bottled live phyto runs $25 per bottle and lasts 4-6 weeks. A DIY phyto culture produces unlimited phyto for the cost of fertilizer ($1/month).
Vessel choice
Best: 2-liter clear soda bottle (free), recycled wine bottle, or glass mason jar. Larger = more harvest. Run 2-3 bottles at once for redundancy.
Lighting
Continuous 24/7 light. Use a small 6500K LED desk lamp positioned 4-8 inches from the bottles. Cost: $15-25. Cheap shop light works fine - phyto isn't picky about spectrum.
Aeration
Air-stone running 24/7. Vigorous bubble - phyto needs CO2 + agitation. 2 bottles + air pump + Y-splitter = ~$25 setup.
Fertilizer (F/2 medium)
Buy F/2 part A + part B from BulkReefSupply or Florida Aqua Farms ($25 lifetime supply). Add per instructions when starting the culture + once weekly.
Alternative: Miracle-Gro hydroponic fertilizer at 1/4 strength ($8) - works but less optimized.
Strains to grow
- Nannochloropsis - 3-5 micron, primary copepod food
- Tetraselmis - 10 micron, larval clownfish food
- Isochrysis - 5 micron, clam + filter-feeder food
Buy starters from BBcorals, Reef Nutrition, or AlgaeBarn for $20 each.
Harvest schedule
Once the bottle reaches dark green color (2-3 weeks from start), harvest 50%, replace with fresh saltwater + F/2. Refrigerate harvested phyto - lasts 4-6 weeks at 38°F.
Dose to display: 5 ml per 10 gallons daily. Good for clams, filter-feeder corals, NPS gorgonians, sponges.
Crash recovery
Cultures crash. Always run 2-3 bottles offset by 1 week. If one crashes, you reseed from the others. Sterilize crashed bottle with 10% bleach soak 24h before restarting.
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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.
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