Feeding a calcium reactor with a Nitrate reactors effluent

Answer:

Hi Caroline

If you are going to try this i would connect the nitrate reactor via a T
piece to the input line of the calcium reactor,
this way your reactor output wont be governed by the output of your Nitrate
reactor which will probably be too low
to keep up with Calcium demand for your aquarium.

By connecting the Nitrate reactor directly to the calcium reactor you will
remove effluent adjustability from your Ca reactor.

The other problem would be that by setting up this way you wont be able to
gauge the effluent rate through the Nitrate reactor.

With regards to the thinking behind running the Nitrate reactor effluent
through a calcium reactor media this may be advantageous
depending on the type of reactor that you run. Sulphur driven reactors can
pull down alkalinity by utilising carbonates/bicarbonates
as a form of inorganic carbon for nitrate reducing bacteria as an additional
energy source.
 Due to this effluent alkalinity/Ph can be low thus running the effluent
through aragonite/ca media may liberate a little CA/Alk from
 the aragonite media to help reduce this effect.

If using a Carbon fed reactor this isn't an issue as there will be carbon
available to the Nitrate reducing bacteria and Alkalinity isn't
usually effected. Ph of the effluent may be low but this will soon recover
on contact with the aquarium water, if gaseous exchange at
the aquariums water surface is good and ambient CO2 in the house isn't high
any low Ph effluent from either the Nitrate reactor
or Calcium reactor shouldn't become an issue if set up correctly.

If you still wish to run you Nitrate reactor through Calcium reactor media
then i would suggest setting up a small vessel to run the effluent
into, fill the vessel with calcium reactor media and allow the effluent to
run through this and back into the sump. This will allow the effluent to
pick up a little Alkalinity and will help the effluent come to equilibrium
with atmospheric O2/CO2 to bring the effluent Ph up.

As i say though this may only be of any real benefit if running a sulphur
driven reactor.

Hope this helps
Tony