Frags are how coral livestock moves through the hobby. What it is: a 1-3 inch portion of a parent colony, attached to a ceramic frag plug or piece of rock. Cutting methods: bone cutters (for branching SPS like Acropora), tile saw (for solid colonies + chalice), banding saw (specialty). Always rinse fresh fragments in iodine + dip in CoralRx or Bayer to disinfect. Mounting: superglue gel (most common), epoxy putty (for heavy frags), thread + frag plug (for delicate corals like leathers). Frag plug: 1-inch ceramic disc with a 0.5-inch stem. Stem fits standard frag rack holes. Frag tank: a separate display dedicated to growing out frags before sale or transfer to display. Often heavily lit + low rock for max grow-out. Frag swap: in-person event where reef hobbyists trade/sell frags - common at local reef clubs. Pricing tiers: common $5-15, named morph $30-150, designer $150-3000+. Sources: Battle Corals, Tidal Gardens, Top Shelf Aquatics, ORA, World Wide Corals (WWC), Vivid Aquariums, Premium Aquatics.
Reviewed by the Fast Aquatics husbandry team · Updated May 2026
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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.
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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