Fish Breeding Master Guide

Guppies are by far the easiest. They are livebearers (no eggs to manage), spawn every 4-6 weeks without any trigger, and need only a 10-gallon tank with dense floating plants. One female can drop 20-60 fry per cycle. Most first-time breeders succeed with guppies within 2 months of setup.

No — bettas need a dedicated breeding tank (10 gal bare-bottom, low water depth, no current) and the female must be removed after spawning. In a community tank the male becomes extremely territorial and will kill tank mates while guarding his bubble nest, and the eggs/fry will be eaten by other fish.

Time to sellable size varies by species: guppies 60-90 days, bettas 90-120 days, tetras 90-150 days, American cichlids 120-180 days, goldfish 180-365 days, flowerhorn 180-365 days (to show the kok hump), arowana 12-24 months. Faster growth requires warm water, frequent feeding, and large water changes.

For egg-scatterers (tetras, goldfish) and bubble-nest builders (bettas) — YES, separate tank is required because parents eat their own eggs or fry. For livebearers (guppies, platies) — a breeding net or dense plants in the community tank works. For substrate spawners (cichlids, flowerhorn) — many do well in their home tank if no aggressive mates are present.

Most tropical fish spawn after a temperature change that mimics seasonal shifts. Common triggers: betta (raise to 28°C and lower water depth), tetra (24-26°C with a large soft-water change), cichlid (cooler water change simulating rainy season), goldfish (cool to 18°C then warm to 22°C simulating spring). Sudden 2-3°C drops + fresh water often work better than constant warm water.

For first 1-2 weeks: infusoria (microscopic) for tiny fry like tetras, newly-hatched brine shrimp (BBS) for larger fry like guppies and bettas. Week 3-4: crushed flake, micro pellets, daphnia, finely chopped bloodworm. Feed 3-5 small meals per day — fry need constant food but produce a lot of waste, so small meals + daily water changes prevent ammonia poisoning.

Common causes: (1) water too hard or wrong pH (tetras need soft acidic, livebearers need alkaline), (2) no temperature variation (constant 27°C tells fish to never spawn), (3) only one sex present, (4) fish too young (most species need 6-12 months to mature), (5) malnutrition (without live/frozen food conditioning, fish skip spawning), (6) stress from tank mates or wrong tank size.

Yes — especially guppies, bettas, and cichlids. Guppy fancy strains sell $0.30-$0.50/fish wholesale, $1-$3 retail. Halfmoon and koi-galaxy bettas $5-$25. Convict and angelfish cichlids $1-$5. The market in Phnom Penh, Siem Reap and Battambang demand premium strains year-round. Start small (1-2 pairs of one species) and scale based on what sells.

A female guppy can hold sperm for 6+ months from a single mating, so she may keep producing fry every 4-6 weeks even after the male is removed. This is called sperm storage. If you bought a "female only" tank from a pet store and they later drop fry, that is why — she was already mated before being sold.

Convict cichlids: $30 starter pair + $50 tank setup → 100+ fry per spawn, sell $1-$2 each = $100-$200 per spawn cycle (every 6 weeks). Angelfish: $40 starter pair + $100 setup → 300+ fry per spawn, sell $2-$5 each = $600+ per cycle. Flowerhorn: $200+ starter pair + $300 setup → 200+ fry but only 5-10% are show-grade ($50+ each), rest pet-grade $5-$15.