Ca Reactor theoretical max tank calculations??

[McPuff]

I haven't been able to find a suitable answer to this question searching the internets...

How do I know the capacity (or tank size equivalent) for a calcium reactor. Besides the manufacturer's recommended tank size, how can you really know the max size for a Ca reactor?

I'm guessing the answer most will give is to use the largest chamber you can, especially for a large tank. It will depend on your corals' demand for alk and ca. This I understand... and at a certain point, a reactor that is deemed "too small" will simply not be able to provide sufficuent Ca and Alk to keep up with demand. And you can only drop the pH in the chamber before you start to melt the media too much... that seems to be the fail point.

What I really want to know, is if there is a way to calculate the theoretical max tank size for a particular calcium reactor. For this we'd need to know the diameter and height of the chamber along with the amount of media the container will hold. Based on some info I have found, it seems that a taller reactor will have a higher theoretical max tank size than a squatter reactor, provided they hold the same amount of media. The taller reactor is more likely to equally disperse flow throughout the entire chamber.

Anyway, let me know if I'm missing something. My understanding of ca reactors is pretty good but I'm looking for some more concrete numbers and means of calculating efficacy. Thanks in advance.

[tkeracer619]

It's not really about the output but how willing you are to refill the media.

My MRC CR2 was driven to what I feel was the max sustainable on my 360gal stuffed full of sps that grew like weeds.. I was filling the chambers almost every month. Gas rate was almost maxed out from a carbon doser and my masterflex was working to get effluent through fast enough.

This was after close to 8 years of growth and the tank required trimming every month.

I plan on using the same reactor on my 600 with a 100gal frag flat but I know I'm going to have to go bigger after a few years.

[ca1ore]

Low pH water circulates many times faster through the media than it exits as effluent, so I see no reason why the shape of the chamber would make any difference, assuming an equivalent volume of media. Sizing a CaRx runs into the same problems as skimmer sizing. It's not a volume problem, rather a bio load problem. Also, a reactor can be 'pushed' to generate more minerals, though of course there's a limit beyond which even pushing fails to keep up. I've not the foggiest idea how to calculate the right sized unit though.

[OrionN]

The limiting factor here is how to get the CO2 to dissolve. When you add the CO2 too fast of a rate, the propeller of the circulation pump will not be able to get all the CO2 bubble to completely dissolves. When add the CO2, if you add it through a capillary tubing to a fast moving area of the reactor (right before the propeller) you will not have problem with CO2 not completely dissolve.
This minor modification drastically increase the output of any Ca reactor.

[McPuff]

Originally Posted by OrionN

The limiting factor here is how to get the CO2 to dissolve. When you add the CO2 too fast of a rate, the propeller of the circulation pump will not be able to get all the CO2 bubble to completely dissolves. When add the CO2, if you add it through a capillary tubing to a fast moving area of the reactor (right before the propeller) you will not have problem with CO2 not completely dissolve.
This minor modification drastically increase the output of any Ca reactor.

If you post a pic that will help... but I believe that I have mine set up just as you describe. But CaRx can be very tricky and confusing for newcomers so any help is always appreciate in my opinion.

Additional question - do most people use an extra effluent chamber to blow off any remaining CO2? I have another small chamber that I have built specifically for this purpose and figured I might as well use it. Just need to put it inline. I figure it can't hurt.

[OrionN]

Here you go:
This is a picture of the CO2 input. The CO2 feed through capillary tubing rather than regular tubing to the part of the plumping where there is a lot of circulation. This result in a steady stream of tiny bubbles which is much easier for the propeller to handle. I can really add a lot of CO2, thus really lower the chamber pH without having excess CO2 that vented out. I add a steady stream of bubbles to my reactor and never have any excess CO2 that vent out with my reactor. It keep up with huge demand from my T. Gigas (30 inches) and loads of SPS.

[ca1ore]

Interesting idea.

I also keep my chamber under slight pressure (3 psi on the gauge) which helps dissolve the CO2.

[McPuff]

Thanks for that. I do not have a smaller tube like that, but I do have the CO2 going in to an area of high flow and that is situated upstream of the circulation pump. I have not noticed any bubbles within the chamber so it must be doing a good job of dissolving the gas.

Curious what pH you run within your chamber. I try to keep mine about 6.60. Do you also run an extra effluent chamber?

[OrionN]

The small tubes are flow restricters for RO system. You can order them online. They will fit perfectly in standard 1/4 inch RO tubing. Perfectly place at any of the connection.
This modification drastically improve the efficient of Ca reactors. I always have large tank full of SPS and clams, 420 gal before now 320 gal. My Ca reactor easily keep up with demand with a lot of spare capacity. It is only a 6 inchesX18 inches common GEO reactor with this modification.

[OrionN]

in this modification, I took the bubble counter off. In it's place I placed straight inline CO2 input with the micro tubing threaded from there to the main circulation plumping of the reactor. The segment before the intake of the circulation pump. You don't want any water flow through the micro-tubing.