Calcium Reactor Questions

[sacramonel]

I was looking at calcium reactors online today and have a few questions.

Firstly I understand that a calcium reactor is basically a chamber in which a calcium enriched supplement (crushed coral) is immersed in pumped in aquarium water. Within the chamber the supplement is binded with CO2 which is brought in externally. Within the chamber a reaction occurs between the supplement and CO2 that causes a form of Calcium to appear (do not know exact name. I believe it is bicarbonate) and this form of calcium is then pumped into the water column to be then used by the inhabitants of the aquarium.

My questions are as follows -

a. With the use of a pressurized CO2 cylinder wouldn't the amount of CO2 have to be regulated to keep the PH from crashing? If this is correct wouldn't a regulating system(such as the neptune controllers) be an absolute requirement?

b. Since the reactor is basically a chamber in which aquarium water is pumped into the chamber, around the media, and back out, would a DIY modification of say a Phosban Reactor be more practical than spending $300 on an expensive reactor? This modification would include a solenoid valve and attachment to the chamber to pump in the external CO2.

 

[SkiFletch]

a. If you use a decent quality CO2 regulator and decent quality needlevalve to control the flow of CO2 you don't necessary need a controller to operate the unit. You do however NEED a pH probe to measure the effluent pH (stuff that comes out) and adjust your CO2 flowrate accordingly. I believe you're looking for a pH of about 6.5 coming out of the effluent. A controller with a solenoid valve is by far the safest measure, but not always necessary.

The reactions are simple inside a Calcium reactor. CO2 is pumped into the aquarium water. When CO2 is dissolved in water, it obviously creates an acid and lowers the pH. The media is Calcium Carbonate (aka crushed coral) and calcium carbonate in acidic water literally dissolved into it's two seperate ions, Ca++ and 2CO3. That liquid is then dripped into the aquarium to suppliment both calcium and alkalinity.

b. You CAN, but you need to do the modifications VERY well. If you're good at working with acrylic I'd say go for it, if not, I'd beware. The last thing you want is to do something wrong and crash your tank with a low pH.


A couple points of note on calcium reactor usage:

- It is not uncommon for the pH of the display tank to be lower than normal (7.8-8.0) because of the exess CO2. In general saltwater aquaria don't seem to mind this so long as the pH remains stable. If the low pH does concern you, consider supplimenting with Kalkwasser to help counter it.

- If you try and drive the reactor too hard by either pushing too much water through it, or too much CO2, your substrate can quickly turn to "mush" and be difficult to dissolve and dose. Most reactors have reccomended CO2 and H2O flowrates for operation, so make sure you stick to those to avoid problems.

- If you're trying to grow some major acropora garden or tank FULL of hard corals, even a calcium reactor may not keep up with your tank's calcium, alkalinity, and magnesium demands. If this ends up being the case, you may have to resort to adding a second reactor, adding kalkwasser, or dosing a common 2-part additive in addition to the calc reactor.

 

[sacramonel]

Thank you for the response. I'm not ready for the reactor yet as I am still low on the calcium loving corals. I was thinking ahead untl when I do. Also I believe my calcium levels are at acceptable levels now. I do not test, but everytime I use a calcium supplement it quickly coagulates. I read somewhere that means that there is an abundance in the water.

I think I'm going to try the mod. Drilling acrylic isn't very difficult. I have helped friends set up freshwater planted tanks that involved CO2 supplimentation and I think I can use the same concept here.

As for the controller I can see how it is not necessary but definitely useful. I am attempting to have my aquarium be as hands off as possible. I do not like tinkering with it too much. A controller, like the neptune, could help me or anyone with ph, temp, and calcium suplementation.