Homemade Calcium Reactor 11/23/08
I've been trying to come up with a simple, cheap homemade calc reactor by searching your site and others.
<A very doable, worthwhile project.>
I had an idea for using an area of my sump to accomplish what a calc reactor would. When I built the system, I subdivided my sump (30L glass aquarium) creating an area for a refugium. I haven't been using it as such because I was lucky to get some live rock with brown macro-algae growing in my main display tank. It looks great and does a good job keeping nitrates (always test at 0) in check.
<Great.>
The refugium chamber has a deep sand bed and some live rock in it, no lights or macro, water circulated through off the main return pump. I have limited space, also driving my desire to utilize a portion of the sump for this purpose.
My idea is to do the following:
1) Greatly reduce the amount of water circulating through the refugium
chamber from the return pump
2) Replace the sand bed with reactor media
3) Pump CO2 into the reactor media through airstones
4) Use a powerhead to circulate water through the reactor media
My main concern is whether or not there will be adequate contact time and dispersion of the CO2 to make an impact.
<You will have trouble getting the ph consistently low enough. The chamber being open along with the powerhead will promote too much gas exchange, causing lower CO2 levels than needed. You will want a finer flow control also, something that can be measured/quantified.>
My tank is a lightly loaded 90 Gal. My calcium demands are low today, but will be increasing as I intend to continue adding corals to the tank. I have been using B-Ionic to supplement calcium. Curious what your thoughts are on this approach. Thanks as always for providing the wealth of information on your site and the opportunity to get specific answers to crazy ideas.
<Heee, welcome. Sometimes crazy ideas pay off big-time! Building you own reactor is fairly straightforward and worth doing. It sounds like you have been looking at the net for the plans, go for it!>
slkem
<Scott V.>

A Ca reactor second chamber  2/5/07  DIY add-on
I am running an octopus Cr 100 recirc calcium reactor on my 600 litre heavy stocked predominantly SPS system. The reactor is rated for 100 litre system (really dunno why reactors are rated for system volume and not caco3 consumption rates, but that for another day).
<Good>
The reactor is barely keeping up with my demand for calcium. I recently  molded two gravel siphons into an add on chamber for my reactor. It has the effluent from my reactor entering through the bottom and after passing through the media, runs past my probe and drips into the sump.
My alk reading of my effluent went up from 25dKH to 32dKH after doing this..... Not sure if its because of the new fresh media or increased contact time with aragonitic media.
<Likely a bit of both>
Should my pH controller be set at a slightly higher pH, as its situated in this passive reactor?
<Mmm... no... I would leave as is>
Will this second chamber increase my effluent (ultimately tank ) readings for Calcium?
<I would not be at all surprised it did so... at least at first...>
Would it be advisable to put a small recirculating pump on this chamber as well, as when i shook it tonight, i noticed a white powdery aragonite settlement at the bottom, which will surely be more beneficial in the tank than in the "reactor".
<I would leave this be as well... the "dust" will either go into solution and be distributed, or not>
Would really appreciate your input.
Thanks for your advice
IVAN
<Welcome. Bob Fenner>

DIY calcium reactor   2/9/06
Hi Bob,
  Love ya love your site.
     I have a question about the DIY calcium reactor. Do you just use regular vinyl tube?
  I see this CO2 "safe" tubing now.      http://www.marinedepot.com/md_viewItem.asp?idproduct=CO1515
     Do you really need this? It is sort of expensive.
     Thanks,
  Ed
<You can use such vinyl tubing (better the stuff made for carbon dioxide supply), but it will "stiffen" and have to be replaced more often. Perhaps every year or two. Bob Fenner>

- DIY Calcium Reactor Question -
<Greetings, JasonC here...>
I have made my magnum 350 into a calcium reactor by making a manifold out of pvc, to inject carbon dioxide, an outlet for effluent, and a dedicated pump for intake. Seems to be working well.  I have also put a passive reactor in the effluent line to rid the system of residual co2.  The system has been up and running for about a week.   I read your FAQ's, and it seems that people are getting really hard water out of their systems.  Does this take time? <Days...> My dKH is only 13. <A little on the low side, but not terrible to add to your tank.> The tank (full-blown reef) dKH is 7.  Calcium is 450 ppm, but so is the tank. <Ahh, the improved alkalinity will help, though.> I am dosing 25 bpm.  About 60 drips per minute. Effluent ph is 6.5 or so. <Be careful, you don't want the pH much lower than that.> Media is Korallith.  Do you think that the hardness will increase with time? <No... you need to look at how you might keep the water in the reactor a little longer. Most commercial reactors a recirculation devices, with the water in the reactor turned over several hundred times an hour. If your magnum is hooked up in the standard loop to your tank, you are likely not keeping the water in the reactor long enough to react with - hence the need for such a high rate of CO2.> I used to use Kalk exclusively, and am still dosing periodically, hoping the calcium reactor will catch up. <A couple of tweaks to the design and you will be fine.>  Any help is appreciated.  Thanks in advance.
Mike
<Cheers, J -- >

- Re: DIY Calcium Reactor Question -
The magnum is not in the standard loop like it normally would be.  I simply took the output, and put it into a pvc loop, right back into the input.  A dedicated pump feeds the manifold. I have co2 going into the manifold, and a cinch valve for the output, also in the manifold. So, I can keep the water in the magnum for as long as I like. <Ahh, ok... makes sense.> What should the "targets" be? <You mean for pH and alkalinity out of the reactor? 6.7-6.8 pH and alk. in the 15-17 range would be perfect.> LFS says that 450 ppm calcium is great, you sound like it's a bad thing? <No, no... just that your alkalinity in the tank was a little low, but the calcium reactor will fix that in time.> A little confused, here. <No worries.>
Thanks again
Mike
<Cheers, J -- >

DIY Calc reactor
Greetings,
Do you have a diagram or pic of the DIY calc reactor your club has been making. I am part of a club here in Michigan ( http://www.wmmac.org ) and would like to entertain the idea of doing this project with our club as well. I have examined the Sanjay's calc reactor design and was wondering how is it modified from that?
Thanks A lot,
Jason

Re: DIY Calc reactor
There are some pictures on our club website...
www.marineaquarist.org
Click on the tanks section of the photo album. Click on the CaRx DIY link. This is an older version of the design. Bob Fenner took some pictures of the newer version. They were on his website...
www.wetwebmedia.com
I could not find them. He may know where they are. <<They can be found here: http://www.wetwebmedia.com/calcreactors.htm >>
The main difference between the design pictured and Sanjay's design is that the recirc loop is inside the reaction chamber.
The main differences between the design pictured and the current design are...
All the water and C02 taps are 3/16 ridged air tubing taps. The water and air flow rates don't require anything bigger. They're simpler too. Just drill a clean 3/16 hole and friction fit a bit of ridged air tubing into it. You can put a little two part clear epoxy resin around them if you are concerned about leaks.
The pump is the Rio 600 AV. This model has two venturis built in. One is
attached to the CO2 tap. The other is attached to a tube that runs up into the cap to scavenge C02 gas that has collected there. There has been some concern that the flow rate stirs the media up. I put filter pads on either side of the media.
Use clear tubing for the riser so you can see the CO2 being mixed in.
Use a 4" cap instead of a 4" coupler for the bottom. It is simpler and works fine.
<<Thanks for sharing - cheers, J -- >>

DIY Calcium Reactor?
Quick Question, do you think that I can make a calcium reactor out of an old Magnum 350 canister filter by just using the canister for the media for crushed coral.
<The media is unlikely to dissolve at normal aquarium pH's. That is why calcium reactor inject carbon dioxide, CO2, to create carbonic acid, low the pH inside the vessel, and dissolve the media.>
Thank for your time and effort, Tim
<You are welcome. -Steven Pro>

[SDMAS] Calcium Reactor Workshop Signup (Southern California)<Old>
<Thanks much John. Will post on WWM. Hope to see you soon. Bob Fenner>
CALCIUM REACTOR WORKSHOP
Now is the time!! Please sign up for the workshop if you plan on building a reactor!
On July 20 at John Foster's house in the Hollywood Hills, MASLAC and SCMAS will host a calcium reactor building workshop followed by a BBQ. You do not need to build a reactor to attend. You can feel free to be an observer or just come for the BBQ! One word of caution: If you do plan on building a reactor someday, DO IT NOW. We are getting great prices, there will be many people there to help those that want it, and we will have all the pieces cut and purchased for you. To do this on your own "someday" will likely be harder and cost more!! If you can't make the workshop but would like to make a reactor, sign up and pay so I can buy your parts and we will work out assembly at another time. I will only be buying the parts once.
The Complete reactor (everything except CO2 tank and reg) will cost $110 (there maybe a slight refund if parts come in cheaper) (clear water filter cylinder $22, Mag 3 pump $40, misc. plumbing and supplies $48)
Plus for those who need it:
A special deal on the CO2 tank, regulator, solenoid and needle valve $154 (5lb tank $69, Regulator Combo $85)
If you get both you have a complete setup ready to turn on when you get home!! Operating instructions will be included.
To sign up:
1. E-mail me now drjohnf@att.net stating what you are buying, or that you will be an observer only.
2. By June 28th send me a check for the amount of your purchase. Send to:
John Foster
2801 Pelham Place
Los Angeles, CA 90068
Attn: Calcium Reactor
Thanks, a map to my house is attached and a schematic of the completed reactor is attached.
If you are using mapquest, it will show you the correct location but give you a terrible route from Beachwood Drive. Use my map from Beachwood to my house.
John Foster

Yeast Calcium Reactor
Hi Bob,
I was still dreaming about my future calcium reactor when I stumbled across the idea of yeast as a C02 source. Do you have any experience with this kind of calcium reactor setup? 
<Yes... actually a great deal...>
I checked on a couple of the DIY sites, and it seems simple enough. However, some of the sites also posted horror stories of the yeast bottles exploding and turning homes into breweries!
<Explosions are exceedingly rare... easy though to make, transfer alcohols>
What do you think? If this is relatively safe and effective, I figure I could put together a DIY reactor for less than $150. Thanks in advance for the advice.
<Worth experimenting with, but really, a bottled carbon dioxide system is what almost everyone wants, needs... much easier to control, use. Bob Fenner>
Khoi

(DIY) Calcium Reactor Questions
1. If you over drive your calcium reactor does the excess calcium precipitate on the water surface or attach to everything like Kalkwasser drips?
<Mmm, some calcium reactors, various feed stocks can be made to do this... but not practically>
2. What is the maximum saltwater can hold?
<The maximum what? Calcium? Several hundred ppm.>
3. Does salinity (1.019) or water temperature (76-80) play a significant factor?
<In saturation, introduction of biominerals (alkaline earth elements)? No, not "significant" in hobbyist/husbandry terms>
In preparing for a larger main tank I have built a six foot tall calcium reactor. 
<Six foot tall? Unnecessary. Was at a local marine club meeting a few days back just to give you an example. The owner had a 1,200 (twelve hundred) gallon system with a two foot high Knop unit...>
Poured 50 pounds of Geo Marine in it then I pushed the affluent
<Is it rich? Effluent likely>
PH down into the 6.5s while maintaining a fair water flow.
Within 24 hours I now have what feels like sandpaper grit accumulating on the water surface in the sump. Is this related?
<Yes>
Fish seem OK. Has anyone else felt this on the water surface? Sump is in the garage.
Will this turn my plenum into cement?
<Don't know about the latter... but you don't need, want this much feeder stock, this low a pH effluent... Experiment a while... perhaps on a non-living set-up. Bob Fenner>
Thanks,
Steve Heathcote