For the purpose of coral dipping you should only be using a 3% concentration of Hydrogen peroxide. The dipping duration should be no longer than 5 minutes.
The dilution rate is 1L of tank water combined with the suggested peroxide dose below.
Low 20-40ml
Acropora (tolerance varies widely among species), Montipora, Astreopora, Duncanopsammia, Turbinaria, Galaxia, Cyhpastrea, Alveopora, Hydnophora, Echinophyllia, Mycedium, Oxypora, Tubastrea,
Low/Med 50-70ml
Pocillopora, Seriatopora, Stylophora, Caulastrea, Clavularia, Pachyclavularia, Sympodium, Cespitularia, Yellow Leathers, Pachyceris, Echinpora, Leptoseris, Pectinia, Psammacora
Medium 80-120ml
Porites, Xenia, Brown Leathers, Pavona, Fungiids, Heliofungia,
Med/High 130-200ml
Goniopora, Favia, Favites, Goniastrea, Platygyra, Leptastrea, Blastomussa, Cynarina, Physogyra, Plerogyra, Symphyllia, Sinularia, Corallimorpharian (Mushroom Anemone)
High 210-350ml
Zoanthids, Palythoa, Scolymia, Acansthstrea, Micromussa, Lobophyllia, Euphyllia, Catalaphyllia, Trachyphyllia
Once the coral has been dipped, wash it off with tank water and place it back in your tank. You will notice, during the dipping and afterwards, bubbles rising from the affected area as the peroxide reacts and oxidises.
Coral can be dipped longer in a lower concentrate solution for up to 20 minutes for deep, persistent algae or bacterial infections, or necrotic areas.