KalkPLUS will raise the pH in your reef tank.


  • Highest grade Calcium Hydroxide
  • KalkPLUS will raise the pH in your reef tank
  • Raise calcium levels
  • KalkPlus contains no Phosphate, Silicate or Nitrate

Poor pH levels can be attributed to many factors. High levels of Phosphate or Nitrate can lower the pH of seawater causing the water to become acidic. This acid dissolves the skeletons of corals and causes slow growth in corals.

In severe cases, it can cause the decline in coral health and lead to the death of both corals and fish. KalkPLUS is made from the highest grade Calcium Hydroxide with unsurpassed purity. Used as directed, KalkPLUS will raise the pH in your reef tank to that found in natural seawater and will also raise calcium levels.

KalkPLUS contains no Phosphate, Silicate or Nitrate

Directions for Use

Never add KalkPLUS directly to the tank. Add 50g to 2litres of purified water in a clean bottle and shake well. There will be a separation after a few hours with a clear part and a milky part at the bottom of the bottle. Drip the clear solution into the tank and monitor pH with OAL’s Marine pH Test Kit. Once pH has reached between 8.3 and 8.5, add only what is required to maintain the desired pH levels.

Do not exceed a pH of 8.6 as this will cause Calcium, Magnesium and Strontium to precipitate into an insoluble hydroxide form. Keep this container tightly closed when not in use. Calcium Hydroxide is caustic. Avoid contact or inhaling dust. Do not ingest or get into eyes. In case of contact, flush area with water for 5–10 minutes. In case of eye contact, wash eyes with water immediately (5–10 minutes) and seek medical attention.


Available Sizes: 250g / 500g