# Nilocg's Rex Grigg Reactor.....



## hedge_fund (Jan 1, 2006)

Colin who is a forum member here (nilocg) has built me a Rex Grigg reactor for my 75 gallon cube. He was doing a test run first to see how it comes out and so far so good. He might start selling these here so hit him up if you are interested in obtaining one. This is probably one of the most efficient ways to inject co2 into your tank. I was previously using the GLA Atomic Diffusers which are amazing but was getting tired of all the little bubbles all over which made my tank look like soda water.

The reactor is being run by an Eheim 2213 and the flow is perfect. As a matter of fact, I do not notice a difference in the flow after attaching this reactor.

Nilocg's contact info:
http://www.plantedtank.net/forums/showthread.php?t=525929

Here are some pics of what arrived and how it's hooked up.

About 20 inches long:



















My tank:


----------



## HybridHerp (May 24, 2012)

So this produced no bubbles what so ever? I assume that it also would help improve the life of the co2 canister since if it has no bubbles it should be more efficient with co2 diffusion.

If it were me though, I think I'd paint the think to match my wall or hide it somewhere or something 

Definitely something to think about in the future.


----------



## hedge_fund (Jan 1, 2006)

HybridHerp said:


> So this produced no bubbles what so ever? I assume that it also would help improve the life of the co2 canister since if it has no bubbles it should be more efficient with co2 diffusion.
> 
> If it were me though, I think I'd paint the think to match my wall or hide it somewhere or something
> 
> Definitely something to think about in the future.


Eventually it's all going under the tank but for now I'm testing it out.


----------



## Solcielo lawrencia (Dec 30, 2013)

It's basically a suspended macro bubble container like the ones you can buy for $12. The downside is that it doesn't have a way to create small bubbles, which dissolve faster due to the increased surface area:volume ratio.


----------



## PlantedRich (Jul 21, 2010)

I think I see better now. I was thinking it was upside down! Can we assume that water comes in at the top and out to the tank at the bottom? 
If you would like to promote the product just a bit, I would be open to hearing more about what comes in the box, price and shipping details if you wish to share that. Already glued or a parts kit?


----------



## hedge_fund (Jan 1, 2006)

PlantedRich said:


> I think I see better now. I was thinking it was upside down! Can we assume that water comes in at the top and out to the tank at the bottom?
> If you would like to promote the product just a bit, I would be open to hearing more about what comes in the box, price and shipping details if you wish to share that. Already glued or a parts kit?


Yep, the water comes in at the top and the bottom is connected to the lily pipe. It's filled with bio balls and was sent to me as is already put together. Hit up Nilocg for price details etc.

You can definitely make these yourself but taking the time to gather parts, glue, pvc pipes and all just isn't worth it for me. I really hope he starts to mass produce these to help out other forum members. He's one of a few sellers here that really promote the hobby with the items he sells.


----------



## Mrnbo (Dec 18, 2013)

What's the difference between this and the Ista max mix?


----------



## tattooedfool83 (Mar 15, 2013)

hedge man, your tank is amazing


----------



## Solcielo lawrencia (Dec 30, 2013)

Mrnbo said:


> What's the difference between this and the Ista max mix?


DIY doesn't chop up the gas into smaller bubbles like the Ista.
DIY can cost more than the Ista.
Ista allows some bubbles to escape. So can DIY.
Ista looks better than DIY PVC.


----------



## KribsDirect (Nov 15, 2013)

Subscribed. I'm interested to see more info as well.


----------



## Mrnbo (Dec 18, 2013)

Solcielo lawrencia said:


> DIY doesn't chop up the gas into smaller bubbles like the Ista.
> DIY can cost more than the Ista.
> Ista allows some bubbles to escape. So can DIY.
> Ista looks better than DIY PVC.


It looked like essentially the same concept to me... Which one is better?
Sorry for the hijack... The tank, as always, looks great hedge fund. Lol I'm hoping I can afford a custom cube one like that someday.


----------



## hedge_fund (Jan 1, 2006)

Solcielo lawrencia said:


> DIY doesn't chop up the gas into smaller bubbles like the Ista.
> DIY can cost more than the Ista.
> Ista allows some bubbles to escape. So can DIY.
> Ista looks better than DIY PVC.


You forgot the most important one of all....

Ista leaks and Ista is a very small reactor. I pump a ton of co2 into my tank and there is no way that an Ista can keep up.

PS. I would love to see your tank and the results that the Ista produces.



Solcielo lawrencia said:


> It's basically a suspended macro bubble container like the ones you can buy for $12. The downside is that it doesn't have a way to create small bubbles, which dissolve faster due to the increased surface area:volume ratio.


I think you're missing the point of a reactor. A "good" reactor will produce zero bubbles since the co2 will get absorbed by the water "inside the reactor". The main reason why I switched to a reactor is to get rid of the bubbles that my atomic diffuser was producing.


----------



## hedge_fund (Jan 1, 2006)

tattooedfool83 said:


> hedge man, your tank is amazing





Mrnbo said:


> It looked like essentially the same concept to me... Which one is better?
> Sorry for the hijack... The tank, as always, looks great hedge fund. Lol I'm hoping I can afford a custom cube one like that someday.


Thanks guys.

With the new reactor the plants are pearling even more. To be honest, the pearling is a bit annoying. I took out my GLA diffuser to get rid of the bubbles but now they are back in a different form....the plants keep pearling like crazy, especially the blyxas which never really did much in terms of producing O2.

I would highly recommend one of these reactors. Whether you get Nilocg to make you one or DIY.


----------



## mott (Nov 23, 2006)

The whole point with a reactor is it's meant to dissolve bubbles, why would you want any size bubble to escape???


----------



## hedge_fund (Jan 1, 2006)

mott said:


> The whole point with a reactor is it's meant to dissolve bubbles, why would you want any size bubble to escape???


This reactor doesn't produce any bubbles...it's all absorbed into the water. I presume you're questioning the Ista user in this thread?


----------



## Solcielo lawrencia (Dec 30, 2013)

I read the links to the original concept of the reactor. Apparently, by removing the bioballs, it became less efficient. And when it became less efficient, the length got longer to compensate. I really hope this doesn't go the way of the razor, from 1 blade to 2. Then the Mach3. Then it was upped by the Quattro. Then the 5-blade Fusion. Then the Hydro... The irony of all these razors was that the more blades were on the cartridge, the worse it shaved.

A compact and efficient reactor could be made if we increased the pressure inside the chamber, like the way soft drinks are carbonated. It's not carbonated by swirling bubbles around for hours. It's carbonated by injecting CO2 into an enclosed container under high pressure. It's fast and efficient.


----------



## hedge_fund (Jan 1, 2006)

Solcielo lawrencia said:


> I read the links to the original concept of the reactor. Apparently, by removing the bioballs, it became less efficient. And when it became less efficient, the length got longer to compensate. I really hope this doesn't go the way of the razor, from 1 blade to 2. Then the Mach3. Then it was upped by the Quattro. Then the 5-blade Fusion. Then the Hydro... The irony of all these razors was that the more blades were on the cartridge, the worse it shaved.
> 
> A compact and efficient reactor could be made if we increased the pressure inside the chamber, like the way soft drinks are carbonated. It's not carbonated by swirling bubbles around for hours. It's carbonated by injecting CO2 into an enclosed container under high pressure. It's fast and efficient.


I'd say that the Rex Grigg reactor is pretty darn efficient. I couldn't be happier with my tank and I am also using half the bps that I had going into an atomic diffuser. The reactor doesn't solely work by swishing the water around...there is a decent amount of pressure in there too. There is a reason why it's still in use for close to 10 years.


----------



## gSTiTcH (Feb 21, 2013)

I built a Griggs reactor. I've been very happy with the results. Only difference is that I run mine on the input side of the canister with no biomedia. Also, I got a nifty little adapter at the top used for drip line irrigation systems to attach the air hose.


----------



## thadius65 (Sep 15, 2006)

I have this reactor (DiabloCanine) with the PH probe addition. I recently set it back up but i don't think i have all the bio balls in it as i am getting major bubbles. Where they large or small bio balls?


----------



## Solcielo lawrencia (Dec 30, 2013)

The size of the balls don't matter.


----------



## thadius65 (Sep 15, 2006)

Solcielo lawrencia said:


> The size of the balls don't matter.


Will refrain from the obvious..... :icon_wink


----------



## rdmustang1 (Oct 20, 2013)

These are ridiculously easy to make. If anyone is interested in doing their own you should also check out Cerges' reactor. It was built to improve on Rex Grigg's design but cost is slightly higher.


----------



## Mark Allred (May 3, 2013)

Picture is kind of dark, but this is my Griggs style reactor. 
24" tall and sits in my 65 High's sump.
The 3/4" outlet loop is to keep a water level in the reactor.
The outlet elbow points directly into my recirculation pumps suction.
It works very well, probably spent about 12 bucks!


----------



## scapegoat (Jun 3, 2010)

Solcielo lawrencia said:


> A compact and efficient reactor could be made if we increased the pressure inside the chamber, like the way soft drinks are carbonated. It's not carbonated by swirling bubbles around for hours. It's carbonated by injecting CO2 into an enclosed container under high pressure. It's fast and efficient.


this isn't an enclosed container though. diffusion of co2 into water in our use case is done through contact w/ water, not pressure. 

the concept of using the bio balls was done to create a way to break up larger bubbles. We could probably do a better job of that w/o the bio balls and using a screen over the injection point.


----------



## Solcielo lawrencia (Dec 30, 2013)

scapegoat said:


> this isn't an enclosed container though. diffusion of co2 into water in our use case is done through contact w/ water, not pressure.
> 
> the concept of using the bio balls was done to create a way to break up larger bubbles. We could probably do a better job of that w/o the bio balls and using a screen over the injection point.


I read about the original concept and design which included bioballs. Then someone decided to improve it by removing the bioballs thinking it was unnecessary. Subsequently, the reactor became less efficient according to the original designer.

The bioballs are not meant to break up larger bubbles. It can't do that. What it provides are two things:
1. turbulence
2. reduced flow = greater pressure

By accomplishing both, dissolution will be faster.


----------



## rdmustang1 (Oct 20, 2013)

Solcielo lawrencia said:


> A compact and efficient reactor could be made if we increased the pressure inside the chamber, like the way soft drinks are carbonated. It's not carbonated by swirling bubbles around for hours. It's carbonated by injecting CO2 into an enclosed container under high pressure. It's fast and efficient.


If space is a big issue then you should have a dedicated CO2 return pump with another pump creating a higher pressure, lower flow like you're saying. Unfortunately this adds a good deal of cost. You should also expect bubbles to appear at the reactor output when the pressure drops as a sudden drop of pressure should allow some CO2 to reconstitute. On my setup, when I turn the CO2 off it takes about 5 seconds for the remaining CO2 to dissolve (not hours). I'm also running a very high CO2 rate as I have 260 gallons to saturate at 30+ppm.




Solcielo lawrencia said:


> I read about the original concept and design which included bioballs. Then someone decided to improve it by removing the bioballs thinking it was unnecessary. Subsequently, the reactor became less efficient according to the original designer.
> 
> The bioballs are not meant to break up larger bubbles. It can't do that. What it provides are two things:
> 1. turbulence
> ...


The reason Cerges works better than Rex Griggs is because there is more water volume/contact area which means the CO2 can be spread out more. Higher water to CO2 ratio means better absorption. In my case the turbulence from the return pump keeps the CO2 well dispersed. I'm sure I could add bio balls but now that I've had mine running I don't see a reason to as they are a pain to get into the reactor (I tried). I don't think they were removed as an improvement but instead as an unnecessary addition. I had almost 2000gph going through my Cerges and the bubbles didn't even make it halfway down the reactor. Adding bio balls wouldn't make it any more efficient. To be honest I was shocked how well/fast the CO2 dissolved. Before I actually played with mine I was planning on having to tweak it a bit for a lot of the issues you are bringing up. None of the issues manifest when tested in real life. I will agree that it's not the most space-efficient design and probably are better solutions. For me, the cost was right as well as having a neat toy to look at. I find it fascinating to watch the CO2 being injected and dissolved in the reactor. I purposefully purchased a clear housing so I could see it happening. Now I can make sure the CO2 is injecting properly and I can watch it swirl around and around.

There are many ways to skin a cat but I'm very happy with the method I chose. It works well on a small, low-flow setup and equally as well on a larger, high-flow setup.


----------



## speedie408 (Jan 15, 2009)

Awesome looking tank bro. I really need to get back into planted tanks . Good stuff!


----------



## newbieplanter (Jan 13, 2013)

My questions for this is how long did it take before u saw results? Were the results measured by a drop checker or just by how the plants reacted? 
I have the Ista an I think it's a waste of money. I waited about a month to see if I would get any change in my drop checker, but nothing. So I went back to the good ol glass diffuser. I don't care about bubbles in my tank as long as my plants use some of the CO2 or all I'm good. So as for gettin rid bubbles I don't have that problem as for diffusers as long as it works an does what it's supposed to do I'm happy my plants are too.


----------



## T Jager (May 23, 2012)

After reading this thread and being tired of atomic fizz bubbles all over my tank I contacted Nilcog and he made me a reactor. Love it. So much more efficient than an diffuser. Looks easy to make but its hard to get to a hardware store when your right leg is in a cast. Been tweaking the co2 in with two drop checkers and testing using the ph/kh chart. If anyones interested he is really easy to deal with and has great prices. So hit em up.


----------

