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Rex Grigg Style Co2 Reactor | Standard Version

Ships in 5-7 days

Product Description

Rex Grigg Style Reactor


Rex Grigg reactors are one of the most efficient methods for diffusing co2.  The standard version is good for tanks up to 75g and canister filters under 300-350gph.  The reactor is designed to be used between the canister filter and the tank on the output side of the filter.  It should be mounted under the tank and needs 18-24" of vertical space.  Water should enter the top of the reactor and exit out the bottom.  If you have any questions about the use of a Rex Grigg style reactor please make sure to contact me prior to purchasing.

The major advantage of the Rex Grigg style reactors, other than near 100% dissolution of co2, is that they require almost zero maintenance and nothing visible in the tank. 

If you have a larger tank with a larger filter please look here for the version with the capacity to handle the amount of co2 and flow used on this size tank:  Rex Grigg Style Co2 Reactor | Advanced Version With By-Pass Valve

 *****The actual length of the reactor will be +/- 0.5", if you have a very tight fit please let me know prior to ordering*****


Should you add the Bio-Balls?  

- This question is fairly subjective.  Some people think it really helps, others thinks it completely unnecessary.  I can see both sides.  In the past I havent offered the Bio-Balls, but have had a lot of requests for them so here they are.  The choice is completely up to you:)

Color of the reactor:  The standard color is black.  I can paint it other colors for an additional cost.  If you would like a different color be sure to check that option above.  Then please include the color which you would like it painted in the comments section while checking out.  Please only standard colors, I will do my best to match the color that you want but I can only guarantee that it will be close. 


 Setup Instructions:

-Mount the reactor vertically(long side up)

-Water should enter the top and exit the bottom

-Once all hoses(filter and co2) are connected then turn the filter on




*Shipping for Rex Grigg reactors is via FedEx or USPS ground shipping

*Because the Rex Grigg reactor is a custom build piece there is a 1 week lead time before these will ship

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Product Reviews

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  1. Best co2 diffusion and best reactor out there 5 Star Review

    Posted by on Jun 21st 2017

    So I could of built my own but when I went to the hardware store they did not have all of the parts I needed. So I decided to get one built by NilocG. This thing is the highest quality I have ever seen. I was using a Sera Flora 500 reactor that I had to turn on 3 hours before lights come on to get 30ppm of co2. Well this cut that by 2/3 I now get 30ppm co2 within an hour. I even had to turn down my bps because this is just so much more efficient at dissolving the co2. If you want the best co2 diffusion look no where else and this is extremely high quality. Oh he even did a custom measurement for me because I had limited space to work with. It fits absolutely perfect. I could not be happier

  2. Perfectly disolves co2 5 Star Review

    Posted by on Apr 17th 2017

    I love this reactor! Glad I bought it and will never look back.. bye bye diffusers.

  3. Well contructed. No leaks. 5 Star Review

    Posted by on Sep 25th 2016

    This was my first time setting up a canister filter and in-line CO2 reactor. I been bought the Rex Griggs reactor here and it is working perfectly.

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