Basic DIY Ca Reactor questions

[ReefSparky]

Hi Everyone! Looks like this is a great place to share information and further the hobby.

I'm going to attempt to copy a picture of the DIY Ca Reactor designed by WmTasker, but in case it doesn't work (I'm new here, as you can see!), here's the link to the pic.


http://www.reefcentral.com/forums/s...=587186&perpage=25&highlight=Mag&pagenumber=1

!

I've read a bit about the operation and chemistry of the Ca Reactor, but having never used one, I'm a bit cloudy about the influent and effluent. I've read the DIY thread, and I've seen the changes that the creator, WmTasker made;--how he decided to put the incoming CO2 line on the pre-impeller portion of the pump (a good idea to atomize those bubbles), and he also added a second chamber. I presume this 2nd chamber is to attempt to raise the pH of the final effluent and to offgas some of the CO2 in the process.

At the risk of seeming dumber than a bag of hammers; it appears from the pic that the device doesn't sit in a sump. The yellow line is the water intake for the reactor from the sump, I presume; and the line with the ball valve is the drip output. Is this correct?

I also wonder about the quantity of water taken up compared to the effluent. Intuitively, it seems that once the yellow tube takes up enough water to fill the chamber, it would only take up new water to replace the very small amount that the unit ulimately drips back into the sump. Is this right? If it is, then the calcuim reactor simply takes a small amount of water and recirculates it again and again, infinitum, to a point where the output is just a result of some equlibrium met in the reactor. I would think with the constant albeit tiny amount of CO2 injected, the pH of the circulating water in the reactor would continue to fall--.

I was sort of thinking of the Ca Reactor moving a similar amount of water as a protein skimmer, or a phos reactor. But a device that outputs such a relatively small amount of liquid, would have a similarly small input as well, yes?

Thanks for listening to me think aloud here, and as you can guess, I'm just looking for some clarification and confirmation of my thoughts before I make this thing.

Thanks everyone

 

[guido_kp]

hello, and welcome to RC!

it appears from the pic that the device doesn't sit in a sump

correct. you could place it in a sump, if you wanted, i guess in case it decided to leak. the only metal i could find on the chamber is in the pressure relief valve (red button on top) and the inlet and outlet have steel threaded inserts, iirc. both of which are already exposed to the water in the chamber, and i never noticed either of them rusting when i had mine running. metal and saltwater = possible harm to livestock, depending on the metal.

The yellow line is the water intake for the reactor from the sump, I presume; and the line with the ball valve is the drip output. Is this correct

also looks right. although when i made mine, i put the water inlet and the CO2 inlet right before the volute on the pump. just made more sense, having the pump draw it all from the same spot.

Intuitively, it seems that once the yellow tube takes up enough water to fill the chamber, it would only take up new water to replace the very small amount that the unit ulimately drips back into the sump. Is this right?

the feed is fed by a pump - be it a "T" off your return, or a second, dedicated feed pump. so its forcing the water thru it. some ca rx do have the ability to draw their own feed water, thru use of a venturi i assume. this one does not.

I would think with the constant albeit tiny amount of CO2 injected, the pH of the circulating water in the reactor would continue to fall

this is why you use a pH controller with an electric solenoid that shuts down the CO2 injection if the pH falls below a set point. a controller is not a must have, but its definately recommended. just one less thing to go wrong...i mean i guess the solenoid could stick open, by that same arguement, but not likely. and the added cost for a regulator with solenoid and a pH controller isnt that much, when compared to your livestock.

 

[ReefSparky]

Thanks for the answers, guido_kp. I didn't realize the "main" pump only served to circulate water.

I like the idea of a T from the return. So THATS what that nylon screw-covered nipple coming off that piece in the Rio parts bag is huh?!?

Do you favor either method--being a dedicated powerhead or a tee off the return pump?

 

[guido_kp]

i dunno about the RIO - never owned one.

i like the return "T" method. i mean, it doesnt take much flow away from the return (you shouldnt rely on the return for flow, anyway), its one less pump/powerhead heating the water, you already have it, so no need to buy another pump ...etc.

i just used a john guest fitting thread x slip, drilled the pvc above the return, tapped it, and teflon taped the JG fitting and screwed it in. i used one with a valve, so i could take the reactor offline and not have water spraying everywhere.

 

[ReefSparky]

Good then, thanks. I'll run the input for the reactor T'd off from the return.

I wonder how it would work if I drilled and tapped 2 John Guest fittings into the "IN" threaded coupling on the pump where I've circled in the pic, and have both water input and CO2 enter there.

This way there are no taps into the body of the reactor housing, and the CO2 and water have a chance to mix a bit from the impeller action, before enterring the reactor.

 

[guido_kp]

it'll work fine, thats how i did mine.

i put the water inlet and the CO2 inlet right before the volute on the pump. just made more sense, having the pump draw it all from the same spot

post pix too. are you hard plumbing it or using vinyl tube?

 

[ReefSparky]

Sorry, I did read that, but I'm unfamiliar with the word volute. The whole meaning of that sentence escaped me! So THAT'S what volute means, huh? LOL

Great. Guess I'm thinking along the right lines.

I'm going to use soft tubing the whole way. I'll post pics as I progress. I ordered the quiet one 1200 pump from Drssmithand foster.com today for $19.99, and I'm going to get the water filter housing from Lowes tomorrow for $57.99.

Thanks again.