Optimize Calcium Reactor: OrionN's modification

[OrionN]

Calcium reactor is a very efficient and cheap way to add Ca, Alkalinity and trace elements to our reef aquariums, especially those that require high level of Ca and Alkalinity input light large SPS and clam tanks. In order to supply this high level, one needs a huge Calcium reactor, or else a very efficient Calcium reactor. After thinking about this and messing around with my reactors for many years, I came up with a modification that will maximize the production of a Calcium reactor with ease.

In order to maximize the Calcium reactor, on must lower the pH of the reactor chamber to a minimal level. The problem with this is that all the Calcium reactors on the market today do not dissolve CO2 efficiently. My modification is very straight forward and involved minimal work and cost an insignificant amount of money. With my modification I was able to use a standard size Calcium reactor, single chamber 6 inches diameter, 18 inches high GEO reactor, to supply a very high demand 400+ gallons system. I am not even running my Calcium Reactor at it at maxima capacity.
Current Calcium reactor add CO2 with standard air tubing which result in large bubbles of CO2 added to the system, right before the circulation pump which is inefficient in dissolving the large CO2 bubbles. My modification involves adding the CO2 via a capillary tube (flow restrictor for RO system). If we add CO2 via capillary tubing to the main part of the circulation right before the pump, the CO2 will be add in a stream of very fine bubbles. The pump will not have any problem dissolves these bubbles into the solution and thus significantly lower the pH of the chamber with no excessCO2 that escapes as wasted CO2.

I modified my Geo Calcium reactor as below
Geo Ca reactor 6 inches diameter 18 inches high. Build in bubble counter removed. Plumbing rerouted a little and bubble counter added at regulator. I also used stainless wing nuts and stainless screws instead of the plastic thumb nuts that come with it.

Here are the relevant attachments. The PVC seen in the circulation part outside of the reactor chamber. Circulation here is top down. Take water from the top of the chamber and feed the circulation pump at the bottom and spray out to the bottom of the chamber. At the 4 way intersection the R side is where the CO2 input, there is a one way check valve so that salt water cannot reflux back and ruin the regulator. The L side is where the water intake pump in from the dosing pump to feed the Ca reactor. At the top of the Ca reactor is the output of the Ca reactor, flow to the high flow area in the sump.

I added the capillary tube just right after the check valve. I tape the tube at the position, but on outside so everyone can see where the capillary tube go. "A picture worth a thousand words" I think this is certainly true in this situation.

This is how the capillary tube would fit in standard RO tubing

Most if not all Ca reactors these day have build in bubble counter. My modification need to be add after the bubble counter. I modified my Geo Ca reactor by remove the build in Bubble counter and add an other bubble counter at the regulator.


With this modification, I can easily add this amount of CO2 to the Reactor without any problem

With this modification, I can easily supply all the requirement of a heavy SPS and huge clams. Prior to my tank crash due to Hurricane Harvey, I had multiple clams with the largest is a 28 inch shell Gigas and a large numbers of SPS in a 320 gal DT. I have no problem keeping up with Ca requirement with single chamber 6X18 Ca reactor. If you have problem with keeping up with Ca need, why don't you give this modification a try.

Happy reefing.

 

[P-Dub]

Interesting. Thanks for sharing.
If you could do a short writeup of your capillary tube build, that would be additionally helpful.

 

[OrionN]

Interesting. Thanks for sharing.
If you could do a short writeup of your capillary tube build, that would be additionally helpful.

This is the write up. I post it here to get more exposure. I also posted it as an article but it need approval before you can read it.

 

[SDK]

Nice job!

Having spent some time keeping planted tanks, I’m surprised that some sort of diffuser is not standard equipment on reef calcium reactors. If they are just bubbling CO2 in it must be awfully wasteful and inefficient....

 

[P-Dub]

This is the write up. I post it here to get more exposure. I also posted it as an article but it need approval before you can read it.

Yes, I understand. What I mean is, specifically, the build of the capillary tube itself. Parts, part source, and installation in the Co2 line itself.

 

[OrionN]

These day, Ca reactor have bubble counter build in. With this we cannot do this modification since it must be after the bubble counter. Also most bubble counter have water flow through it so we cannot add the capillary tube after the counter due to the water flow.
The Ca reactor need to be re-plumb slightly, removal of the bubble counter at the reactor and add a counter at the regulator.
in this picture, there is a line about 1/2 way through the media. That was how much media dissolved in 6-8 months or so and go right into my tank. I added media last weekend.

 

[OrionN]

Yes, I understand. What I mean is specifically the build of the capillary tube itself. Parts, part source, and installation in the Co2 line itself.

You can buy them online. RO supply. They fit right into the RO tubing. You can added at the joint or just add a connector right before it go into the plumping.

730 ML Insert RO Membrane Capillary Flow Restrictor (100 GPD White)

FRCT-730 730ML Reverse Osmosis Membrane Flow Restrictor and Flow Control

www.waterfilters.net

189 ML Insert RO Membrane Capillary Flow Restrictor (18 GPD Brown)

FRCT-189 189ML Reverse Osmosis Membrane Flow Restrictor and Flow Control

www.waterfilters.net

 

[Daniel@R2R Verified Admin]

Awesome! Thanks for sharing!

 

[ReeferBud]

Thanks @OrionN for sharing this idea. I’m personally very interested in understanding and if there’s a way to improve on the calcium reactor design, this could be very beneficial.

I’d like to explore your hypothesis that standard calcium reactors don’t dissolve CO2 efficiently. Is there consensus on this matter? How did you come up with this conclusion?

When I look at my calcium reactor (Reef Octopus SRO 5000D), I don’t seem to notice, at least visually, undissolved CO2 in the form of small bubbles in the main chamber. Perhaps there can still be undissolved CO2 that’s not visible and it would need to remain that way through the main and second chambers and reach the sump in that state.

If in fact, there is still undissolved CO2 reaching the sump and this modification could improve on that, it could be very interesting since it could help with one of the main drawbacks of calcium reactors, which is an overall lowering of pH of the aquarium.

When you made this modification, did you notice an increase in aquarium pH?

The 2nd part I’d like to explore is the notion that more efficient CO2 dissolution will improve the Calcium reactor efficiency and be able to supply a greater amount of calcium and alkalinity. I’m interested in how you came to this conclusion.

The calcium and alkalinity will depend on the pH in the reactor and in a recirculating reactor design, I’m struggling to see how you can achieve greater supply of calcium and alkalinity at an equivalent pH level.

Did you observe a higher dKH in the effluent at an equivalent pH when you made this modification?

Many thanks for sharing this and really interested in your idea and perhaps having some debate and hearing from folks like @Randy Holmes-Farley

 

[OrionN]

Ca reactor is a very good way to add a larger amount of Calcium and Carbonate to your tank, cheaper. A well design Ca reactor is easy and trouble free.

...
When I look at my calcium reactor (Reef Octopus SRO 5000D), I don’t seem to notice, at least visually, undissolved CO2 in the form of small bubbles in the main chamber. Perhaps there can still be undissolved CO2 that’s not visible and it would need to remain that way through the main and second chambers and reach the sump in that state.
....

You have to see undissolved CO2 or else they all dissolved. An exception to this is if you gently rock or shake your Ca reactor chamber, bubbles of CO2 can get loose from the media and bubble up to the top.

When you made this modification, did you notice an increase in aquarium pH?

I don't check pH of my tank, but never have problem with the health of my tank. My coral grow fast and Ca and Alk level remain high where I need them to be.

The calcium and alkalinity will depend on the pH in the reactor and in a recirculating reactor design, I’m struggling to see how you can achieve greater supply of calcium and alkalinity at an equivalent pH level.

you misunderstand here.
My friend did monitor the chamber pH and reported that the pH is lower with the modification at saturation (when he notice CO2 build up). I wish I have a pH probe to do the measurements myself. I am not a gadget person and not a number chaser type of reefer.

The 2nd part I’d like to explore is the notion that more efficient CO2 dissolution will improve the Calcium reactor efficiency and be able to supply a greater amount of calcium and alkalinity. I’m interested in how you came to this conclusion.

This mod is important at near maximum output of the Ca reactor, and can get more Ca from the same reactor. Other than that, the way it add CO2, in small stream of tiny bubbles, it is likely more efficient and does not waste CO2. Because of this all of the CO2 are dissolved until the solution is at maximum and cannot be dissolve anymore. The total amount of CO2 dissolved in a solution of saline at 35ppt salinity depends on the impurities, temperature and pressure. My modification can lower this minimum pH can be obtain by the very simple fact that the bubbles are tiny and easier to disolves. Of course it cannot add an unlimited amount of CO2 into solution. If I need to have more Ca out put, I will reach the Maximum capacity of my Ca reactor too. However, for the same reactor, the maximum output is more with than without the modification.

 

[Cory]

I wonder is the capillary tube just delivering higher pressure co2 so it dissolves quicker? Nice idea!

 

[OrionN]

I wonder is the capillary tube just delivering higher pressure co2 so it dissolves quicker? Nice idea!

The capillary tube does not increase the pressure of the chamber. Chamber pressure depends on the resistant of the outflow and how strong the feed pump is. I do not recommend increase pressure of the calcium reactor chamber to increase CO2 disolves. However, this can be done by restricting the outflow and use strong feed pump. This will increase the chamber pressure and will increase the amount of CO2 dissolves in the chamber.

Pressurized equipment's are tricky. they likely to sprung a leak, then disaster strike.

 

[Vette67]

This is an interesting idea. And I agree in theory that it should be better to deliver smaller bubbles to the pump, so that they dissolve easier. In my homemade reactor, I have my CO2 injected right in front of my recirculation pump, with the idea that the impeller would then “chop up” the bubbles and dissolve them easier. So if I deliver a smaller bubble in front of the pump, it should theoretically dissolve easier.

I am currently struggling to keep up with the demands of my SPS dominant 180, and I have dramatically increased my CO2 delivery to my reactor over the last few weeks, from a rate of one bubble every 3 seconds to now faster than one bubble per second. I may modify my reactor to incorporate a capillary tube into my CO2 line. It certainly can’t make things worse.

Thanks for the suggestion.

 

[OrionN]

I

This is an interesting idea. And I agree in theory that it should be better to deliver smaller bubbles to the pump, so that they dissolve easier. In my homemade reactor, I have my CO2 injected right in front of my recirculation pump, with the idea that the impeller would then “chop up” the bubbles and dissolve them easier. So if I deliver a smaller bubble in front of the pump, it should theoretically dissolve easier.

I am currently struggling to keep up with the demands of my SPS dominant 180, and I have dramatically increased my CO2 delivery to my reactor over the last few weeks, from a rate of one bubble every 3 seconds to now faster than one bubble per second. I may modify my reactor to incorporate a capillary tube into my CO2 line. It certainly can’t make things worse.

Thanks for the suggestion.

I love it if you able to add what you did and how it help or not help here.

 

[Vette67]

I love it if you able to add what you did and how it help or not help here.

I will do that. It’ll take a few days or more to order parts and make modifications, but it shouldn’t be too difficult. I already use RO water line to inject my CO2, which these capillary tubes are designed to fit inside.

I also need to see what the increased CO2 does to my calcium rate. My last Ca reading yesterday was 360. A little low, but not horrible. I have more than one thing going on now too. I have also started dosing Kalk, so multiple moving parts here.

More to come....

 

[OrionN]

The micro-bubbler, I think I am going to name it, would easily handle this amount of CO2. No problem.

 

[Vette67]

Well, my micro-bubbler™ got installed today. I took a before reading of the DKH of my effluent for a true before / after comparison. My effluent is at 15.0 DKH. Probably should be higher given my calcium consumption (a LOT), so hopefully this trick will mean I am dissolving more of the CO2 to be used to react with my media. I'll take another DKH reading of my effluent in a day or 2 and see if it has increased any.

 

[OrionN]

make sur eyou extend the micro tubing long enough to reach the main part of the circulation or else it does not work. The picture above, it look like the tubing is too short (really depends on where you place it I guess) but from the picture and from where you likely place it, it is too short IMO

 

[Vette67]

That may be the case. Where did you buy yours from? This was an Amazon purchase, and it was the longest one I could find, but I see it is only half the length of yours. Now that it is cut in, it would take me only a few minutes to replace it with a longer capillary tube.

 

[OrionN]

here is one