Ca Reactor - Teach me.

[Triggreef]

One of the pieces of reefing equipment I have never learned about. It seems like no my Ca level always drops lower than it should and have to dose extra Ca in addition to my 3 part dosing in order to maintain it where I want it. I'm not looking to do something other than my 3 part. Just thinking about adding a Ca reactor instead of having to dose the extra little bit of Ca.

A good amount of reefers swear by them. Tell me why....... Maintenance involved? Startup cost? (I'm already apex controlled but I guess would need a pH probe?) Cost of running? Cost of media? How long it lasts? Another pump? How many more plugs?? Changing out co2??

 

[CastAway]

I'm still a newb, and have no experience other than using a reactor. I've never dosed alk or Ca. I do does Mg.

I call my reactor an alkalinity reactor instead of a calcium reactor, as the affect on dKH seems much more dynamic to me than Ca, based on CO2 input and effluent output. Not sure I can explain why this may be so, as I think alk and Ca go into solution at the same rate.

Anyway, I have been wondering if Ca reactors are not just old school, antiquated even, and that dosing might be much more effective and contemporary way to go. I've been thinking to transition.

Mine take three outlets; the pH controller, the feed pump and the CO2 solenoid. The controller uses the pH electrod to maintain the pH within the reactor at a level where the media dissolves. If I had it to do all over again, I'd use a second controller and pH probe in the display as the Ca reactor tends to drive pH down, and many offset this by dosing lime water/kalk. In my 210g system, I've changed my bottle three times in two years, and the media may six times. It seems to last quite a while to me, but again, I have no comparisons or other experience.

Things I dislike are the lack of fine control in the effluent output, the lack of fine control in the CO2 input. If I had it to do all over again I'd make to to get a fine control valve for the CO2.

Some people don't bother wih effluent flow control, and instead just let it flow at a max, controlling the pH in the reactor only as the control. I do both, and may be complicating the process for myself.

My two cents on the idea of supplementing Ca levels by adding a reactor is that you will inadvertently, and perhaps uncontrollably affect dKH as well, not to mention pH.

We'll see what the experts say though....

Hope this helps.

 

[Breadman03]

@CastAway , look into using Masterflex peristaltic pumps for your reactor. They are pricey, but they seem to be a huge improvement.

 

[Triggreef]

@CastAway that was very informational and helpful. I didn't realize there was such an impact on dkh as well. So that probably would not help me any then. Now that I think about it I recall reading about several people using CA reactors and only dosing the 3rd part, trace elements via doser. But I would think that would be extremely difficult to find the correct amount of the 3rd part to be dosing.

Looks like the best route for me then is to continue supplementing Ca on top of the 3 part dosing.

 

[d2mini]

I'll try to go over the basics.

Once setup and tuned, I have found that a CaRx is very stable and easy to use. Providing that you set it up correctly and with good equipment. This is not something you can cheap out on or you will be pulling your hair out. The startup cost is higher than two-part dosing, but in the long run it will be much cheaper. All you will have to buy after the initial setup is more media and more C02, both of which are pretty cheap and last quite a while. I would add more media and change out my 10lb co2 tank about every 5-6 months on my 350g system.

Here's some recommended equipment.
1. Reactor - look at GEO reactors.
2. C02 tank - anything, doesn't matter.
3. Regulator - there is a thread on another forum that shows you how to build an awesome dual stage reg for the same price as the cheap single stage regs. You can also buy an Aquarium Plants Carbon Doser regulator for the same price but it still utilizes a cheap single stage reg. Built it yourself and you will have something that will last you a lifetime and be very high quality.
4. Feed Pump - this is where many people have problems and why they get fed up. You have to have a consistent flow and one of the best ways to achieve this is with a Cole Parmer Masterflex peristaltic pump. They can be found used on ebay for around $250 complete with head, if you are patient. They are completely rebuildable and meant to run 24/7/365. They are ultra precise (used in the medical community) and allow very fine tuning.
5. ph probe to measure the effluent
6. optional controller - many people like to hook their CaRx to a controller. If ph of the tank drops too low the controller can turn off the CaRx. I personally never bothered with this. I just had a ph Monitor on the CaRx to monitor the effluent ph and make sure I was in the correct range for dissolving the media.

Initial setup and tuning will take some time. You will need to test your Alk twice a day in the beginning. As you start to get it dialed in you can cut back to once a day, and eventually you can cut back a little more.
Once it's tuned, all you will need to test is Alk. Alk and Calc (and some other minor trace elements) are added in the proper amounts. You should never have to correct for one over the other. I test alk every few days and calc something like once a month just to see where it is.
Mag you will still need to test occasionally. Some people even add around 5% mag media to their reactors. This can be a little tricky though because if you add too much, it's a pain to remove later. The whole reactor will have to be taken down and reset back up.

If you have the room, and you have the cash for initial startup, I highly recommend a CaRx, especially for a larger sps tank.
It's a no brainer on your size system.

Hope that helps!
Will probably spark more questions so feel free to ask.