Deltec PF509 Calcium Reactor


Why does Deltec Fluidize the Media? With Deltec Fluidized Calcium Reactors, fluidizing the smaller grains of media ensures that the whole of the surface of the media is always available for reaction with the low pH water within the chamber. On a standard non fluidizing calcium reactor the water always finds the easiest route through the media and forms channels or tracks which can result in only a small area of the media being utilised.

Deposits of fine media build up within a standard reactor which choke up the pathways further and require regular maintenance and cleaning out to maintain a reasonable level of efficiency. With Deltec calcium reactors the fine grains of media are kept in suspension and pushed out of the reactor with the water which means that the media never needs to be emptied out and cleaned but simply topped up. 

The Deltec PF509 Calcium Reactor is the starting model of a new fifth generation of Deltec Fluidised Calcium Reactors which now comes with a full bayonet fitting on the top for full and easy access to the media. The Deltec PF509 Calcium Reactor is suitable for tanks up to 500 litres, so is great for those with a smaller tank who may upgrade.

It is the 'baby' of Deltec's 5th generation range of Fluidised Calcium Reactors. It is more than capable however of providing the correct level of calcium for a small to medium sized reef tank. It has a new bayonet style fitting which makes cleaning and maintenance quick and easy.

It comes complete with 2kg of Deltec Hy Carb media.

We recommend you add Amercian Marine Pinpoint CO2 Regulator Kit and American Marine Pinpoint pH Controller (includes pH probe), then you will have everything that you need to plug and play.


  • Mk5 Fluidised Calcium Reactor
  • For use in saltwater aquariums only
  • Pump: Aquabee UP 1000 - 07
  • Media volume 2.2kg
  • Dimensions L: 180mm x W: 140mm x H: 500mm
  • For aquariums up to 500 litres

Calcium Reactor Theory and Setup

Calcium Reactors are excellent systems designed to add a steady amount of natural elemental calcium and minerals to a marine aquarium system. This is achieved by the careful addition of CO2 gas to the system seawater, thus lowering its pH to the acidic range and passing this seawater through aragonite coral chips housed inside the reactor (see diagram below).

Because the CO2 treated seawater has a pH in the range of 6.6 – 6.8 (or lower); it will readily dissolve aragonite coral chips housed inside the calcium reactor. This enriched calcium seawater, also called effluent, should be sufficiently aerated to drive off the CO2 and return the pH to the normal range while still carrying the additional calcium in solution before it is re-introduced back into the aquarium.

You will be controlling the pH of the fluid inside the reactor. Generally speaking a pH of 6.6 – 6.8 (or lower) will readily dissolve aragonite media. If the pH of the seawater surrounding the aragonite is too low, the aragonite will turn to “mush” and no longer have fluid flow through the chips. If the pH is too high there will not be a sufficient acid environment to dissolve the aragonite. Trial and error with your brand of aragonite should be performed.

*** Note: Properly designed Calcium Reactor Systems will add natural elemental calcium and minerals to your system and will have virtually no effect on the pH of the aquarium.

There are several equipment considerations:

  • Calcium Reactor
  • Aragonite Media
  • CO2 Bottle
  • Electric CO2 Solenoid
  • PINPOINT® pH Controller

Collections: Marine

Category: Marine, Reactors

Type: Unknown Type

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