# Aqua Medic CO2 Reactor



## Manwithnofish (Mar 12, 2008)

I'm having lots of problems with my *Aqua Medic CO2 Reactor*. Biggest problem is that it has a small pump that circulates H2O into the diffuser to mix with the CO2. The pump not only pumps H2O to the diffuser but also pumps H2O out the small hole where the CO2 tube connects, and therefore puts back pressure on the CO2 tube and closes the check valve. If I turn the CO2 (needle valve) up high enough, it overcomes the check valve and I get CO2 into the tank. If I turn the CO2 (needle valve) down to the proper bubble rate, then it can't overcome the back pressure on the check valve.

Anyone have one of these diffusers (that works properly)? Any recommendations for a better diffuser?


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## ray-the-pilot (May 14, 2008)

Is this the reactor you are using?

http://www.aqua-medic.com/reactor_1000.shtml

Mine works really well and is very efficient. My reactor is on the outflow of my filter outside of my tank. I've noticed water going back to the check valve but there is no problem with back pressure. I don't have a needle valve. I use this regulator (the cheaper one):

http://www.aquariumplants.com/AquariumPlants_com_s_Electronic_Co2_Regulator_p/co2.htm


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## Manwithnofish (Mar 12, 2008)

I have the Aqau Medic Reactor 500. Not the 1000. The 500 comes with a pump and the diffuser. The pump pumps directly into a "T" connector snapped on the top of the pump. The "T" has a larger tube on one side for the water output (going to diffuser). The other side of the "T" is a smaller nipple to connect your CO2 input to the system. The problem is that there is a significant output of H2O going out both sides of the "T" therefore pushing water against the CO2 in the smaller tube. It actually pushes water half way up the tube. Bottom line is that it doesn't work very well. I looked at the 1000 today. It can either be used either external or internal to the tank. I'm going to get more people's views on reactors before I do anything, but my CO2 system is basically non functional until I can figure out how to deal with this reactor...which cost $60.00 by the way.


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## ray-the-pilot (May 14, 2008)

I looked up your reactor and it recommends using it with a pH controller, which I have. I do not have a needle valve, solenoid valve or bubble counter in my set up. These three things are included in the regulator (all electronic). It works perfectly without any problems. I’d definitely recommend it.


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## Manwithnofish (Mar 12, 2008)

Others convinced me at the beginning that I did not want to regulate pH and I'm not fond of the electronic devices. I love my tank setup (regulator and needle valve). However, I did get rid of the cheap JBJ bubble counter. It has no value in line with the Aqua Medic Reactor 500. I'm just opening the needle valve until the CO2 pushes the water out of the (clear) tubing and I can just begin to see the bubbles enter the reactor. Then I watch my CO2 Drop Checker to monitor concentration levels in the tank. I think I can make this work.

Thanks for the help and advice!!


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## Manwithnofish (Mar 12, 2008)

> Mine works really well and is very efficient. My reactor is on the outflow of my filter outside of my tank. I've noticed water going back to the check valve but there is no problem with back pressure.


*What size tank and canister filter do you have?* I've looked at the 1000, but I was concerned about the increased distance the pump would have to pump, as well as the fact that the flow would be pumping up (out of the filter), then down into the diffuser, through the diffuser, then exit the bottom of the diffuser, and then do a 180 to push water back up and over the edge of the tank. That's three 180 turns between the filter and the tank. My Fluval directions frown on that much hose and that many turns. Also, I get junk built up in my filter hoses that I have to periodically flush / clean out. The turns would not help that situation.

*How is your filter / diffuser arranged?*


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## ray-the-pilot (May 14, 2008)

You are right about those 180 deg turns but not about the crud build up. I only notice crud building up in the corrugated tubing that Fluval uses. If you use standard smooth wall tubing, you do not get that strange build up. 

Basically I run the outflow of my Fluval 405 strait into the top of the Aqua Medic reactor. CO2 pumps into the bottom of the reactor and floats to the top. The CO2 keeps recalculating in the reactor until it is completely dissolved (ie. 100%). If you use an uncontrolled amount of CO2 all of it will be dissolved in your tank and that could be a problem. That is why you need a pH controller. When the level of CO2 gets too high in my tank the controller shuts down the CO2. It very accurately controls the level of CO2 to within 2-4 ppm. If you are not going to use a pH controller, then I wouldn’t recommend any in-line reactor as a blip in your needle valve could cause radical (ie lethal) changes in your tank CO2.


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