Questions about Ca reactors

[BCOrchidGuy]

I've yet to find a drawing of a Ca reactor that explains what the parts do, I would like to build one but I don't understand the system its self. I know that it takes tank water and mixes it with CO2 and forces that acidic water through the carbonate material but, is that it? does it just loop it through?

I was thinking about making something along the lines of a Ca reactor but having it run through my freshwater auto top off, just have a bucket with some aragonite and a bit of CO2 bubbling away in there... I figure if it went into my sump then through my pumps etc and then through the water fall back into my tank that should rid the water of excess CO2.... shouldn't it?

[Son Of Skyline]

Try this site...hope the link works


http://www.animalnetwork.com/fish2/a.../2/default.asp

[Delphinus]

The first thing you describe sounds very much like a kalkwasser reactor or stirrer (which runs inline on your topup), and the second thing you describe, is basically what a calcium reactor does.

[DJ88]

BCOrchid,

A few things that I can see won't work with your idea.

just have a bucket with some aragonite and a bit of CO2 bubbling away in there...

With an open topped bucket all you are going to do is send the CO2 bubbling back into the atmosphere. The reason Ca reactors are closed loops and are sealed from the atmosphere is so that the CO2 doesn't come out of solution and lose it's effectiveness at lowering the pH of the effluent. When running a reactor one of the ways to remove CO2 from the effluent when you are returning it into the tank is to allow it to sit in the open air so the CO2 is released prior to entering the tank. To get any noticeable effect by doing what you are saying you'd need to run a massive CO2 system as the bubbles will just go to the surface and pop.

I figure if it went into my sump then through my pumps etc and then through the water fall back into my tank that should rid the water of excess CO2.... shouldn't it?

You wouldn't have to worry about that as there will be very little CO2 in solution. There is nothing forcing the CO2 into solution. By sealing the reactor and chopping the bubbles up very fine you are giving the water in the reactor a much larger surface volume to interact with the CO2.

but having it run through my freshwater auto top off

You are going to want to run it from your tank itself. Most reactors run at about 100ml/min or more depending on tank demands. I highly doubt you are putting that much fresh water into your system for top off. As well I am not positive but using fresh water won't have the same effect in a reactor. I can't say how the whole chemical process will go. but. I'd say no go.

How a Ca reactor works is that it takes a volume of water inside a sealed chamber mixed with media and recirculates that water. Forcing the water to be in constant contact with the media. You then insert CO2 which takes the pH down to a low enough level to break the media down. you then introduce water from the tank and this forces effluent out of the reactor into your tank. in a nutshell that it it.

[StirCrazy]

there is a larger coral frag farm that is exparamenting with using a second Ca reactor on there fresh water top off and they are having some good results from this but it is not enuf to keep up to the demands of a frag tank on its own. like I said it is in adition to a traditional Ca reactor. I was a little sceptical about it 3 months ago when i was talking about it and pounding out Ideas with the owner, but his latest updates are showing good results.

As Darren said they are not as efective in fresh water as in salt water but yes they will do a ok job of remeralizing fresh water and by doing this it will help the main Ca reactor cope with higher demands by giving it a head start with the make up water.

for the average hobiest this is not the path to follow and a traditional Ca reactor will probably cost about 100.00 including the pump to make your self. Don;t worry about weather it is up flow or down flow, or if you have 20 or 60 bubbles per minuit.. this is stuff to worry about when you have nothing else to worry about

I slapped togeather a quick one to get it going and then I started working on one of my own design. to be honest my quick one is doing a heck of a job, it runs at 20 bubbles per minuit and maintains my tank at 450 Ca and 12.6 ALK so in reality I don't need a bigger/better one but I want it

you probably could get what you are describing to work, but you would go throught 10 lbs of co2 in a week and for the reasons Darren mentions.. by closing it in you make it more efficient, and that is the whole idea behind adding a Ca reactor in t he first place... It is a more efficient method of maintaining Ca and Alk. and the traditionl type Ca reactors do this just fine.

Now if Darren ever puts up planes for his new fangled one so we can see how expensive it would be to build and after he does some long term tests in a loaded tank to determin its maximum capibilities, then it might be better to build his new design if it infact is cheeper to build, remeber there is nothing wrong with cheeper if it does the same job

My Ca reactor goes by two different principles which Darren should still be familier with "Brute force and ingnorance" and "go big or go home" I am not worring about weather I get 10 bubbles per min or 100 bubbles per min.. although it would be nice if it is closer to the lower end and I am expecting about 20 bpm but only time will tell. the main drive behind mine was to be able to load it up with 16 lbs of media instead of 4 lbs and still fit it under my stand as I hate it when I have thins sitting out in the open.

Now to answer your question sence I just rambled on for a long time.. basicly you are using C02 to drop the PH of the water in the reactor.. you have a bigger pump (200 to 500 gph) to cirulate the slightly acidic water throught the media. this effect will give you a volume of water that becomes saturated with minerals.

now you also have to have some means of taking a smaller flow from the tank and add it to the reactor.. (I use a small powerhead for this) this is the amount that everyone refers to as a small flow (100ml/min ect.) by adding the tank water to the reactor it is mixed with the mass of recirulating water and very quickly becomes saturated also. Because you added water you will be also pushing the same amount out, which goes back to the tank, this saturated amount mixes with the tank water and adds Ca and other minerals to the tank water.

Steve

[BCOrchidGuy]

Thanks for the replies everyone, I am still considering it, or just keep using a Kalk top off system that seems to be working for me so far.

Doug.