Calcium Reactor Question

[jcarson999]

I was looking at the MRC site at protein skimmers and calcium reators and found a reference to Nilsen reactors. From the description on the site, it appears that the Nilson does basically the same as a Calcium reactor, but without the CO2. Is that accurate? The Nilson setup seems a lot simpler - if they do the same thing, why would I want to deal with a regulator and CO2?

Jim

[Geoff]

well, not really. a Nielsen or kalk reactor is just a way to supplement small amounts of Ca and alk to the system. it only adds the amount of water that is evaporated during the course of the day. tanks with lots of skeleton building corals will quickly outgrow a kalk reactor only. i know i am one of those.

G~

[RWD]

Yup, the Nielson is a fancy shmancy kalkwaser dispenser, not the same as a calcium reactor. As Geoff pointed out, a Nielson adds water to the tank where a calcium reactor recirculates tank water. If the tank evap rate is low, sometimes the Nielson can't add enough kalkwasser to maintain a calcium level.

[tdwyatt]

Instead of Calcium Carbonate, the Neilssen reactor uses Ca(OH)2 in suspension and carbon dioxide from the tank water and the atmosphere to make up the alkalinity portion. CO2 based calcium reactors utilize CO2 to increse solubility of CaCO3 sands so that recirculated high pCO2, low pH water then dissolve the CaCO3 to make a solution of ions of Ca++ and bicarbonate anions.

Many folks use various means of driving up evaporative rates to increase the amount of kalkwasser needed to replace the evaporative losses. As already mentioned, this only will work up to a certain point, then incresed demand outstrips the ability of the neilssen reactor to supplement the Ca and alk.

[jcarson999]

Thanks for the clarifications as to the differences. Now, do I even need a CA reactor if I don't keep stony corals?
Jim

[Geoff]

Originally Posted by jcarson999

Thanks for the clarifications as to the differences. Now, do I even need a CA reactor if I don't keep stony corals?
Jim

probably not, unless you have an absolutely insane population of snails.

water changes can generally keep up with the Ca consumption of FO and softy tanks. kalk reactors are also good at keeping the pH up.

G~