Skip to content
PetLive

Glossary

The words this trade uses, defined plainly and linked from everywhere they appear.

This trade uses a lot of shorthand, and most of it is defined nowhere a beginner can find. Every term here has its own page as well as a line in this list — the page is what a guide links to, so you can read the definition without losing your place in the article.

Why a glossary at all

The words are the barrier

  • Most of it is undefined

    This trade runs on shorthand that is explained nowhere a beginner can find, and then sells to beginners.

  • One page per term

    So a guide can link to a definition without making you lose your place in the article.

  • Written from the tanks

    Each entry says what the word means here, in practice — not what a dictionary would say about it.

  • ActinicThe blue-violet part of reef lighting, roughly 420–460nm.
  • Alkalinity (KH)How much carbonate the water carries, and the single number stony corals care most about.
  • AquaculturedGrown in a tank from a piece of another tank-grown animal.
  • Coralline algaeThe pink and purple crust on established rock — a sign the system is mature.
  • DOADead on arrival — and the policy that says what happens next.
  • Drip acclimationLetting your water replace the shipping water slowly, over an hour or more.
  • FragA piece cut from a larger colony, grown on until it can stand alone.
  • LPSLarge-polyp stony corals — fleshier, more forgiving, and easier to photograph honestly.
  • Polyp extensionHow far the animal opens its tentacles — the fastest read on whether it is comfortable.
  • SPSSmall-polyp stony corals — the demanding, fast-growing, colour-shifting end of the hobby.
  • Sweeper tentacleA long stinging tentacle some corals extend at night to clear their neighbours.
  • WYSIWYGThe photograph is the animal you receive, not a representative of its type.

Where these words come up

View all