Rex Grigg Reactor & Bioballs

rjordan393

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Mar 5, 2013
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Hello,
I am looking for opinions from those who use bioballs or similar media in their CO2 reactors. I am considering stepping up from my 2 inch ID by 3-1/2 foot tall to a 3 inch ID by 3-1/2 foot tall reactor and place bioballs in it, thinking it may help dissolve the CO2 better. Do you know if this idea can work?
 

gsjmia

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Yes, it works fine.

I use Bio-Bale instead of bioballs, easier to clean, but both work.

The only caveat, is that this system works better on its own loop and not in line with a cannister or other filter. The reason being that if its in line with a filter, when the filter gets dirty (as in daily), the efficiency is reduced and the Co2 fluctuates and will cause periodic tank crashes.

If its on its own loop, there is no fluctuation in Co2.

I have a seperate loop into a griggs reactor and it empties into the sump next to the suction for the main pump. I have no end on the griggs reactor and it sits on a poret block of sponge that captures all the microbubbles.

Rather than make a bigger diameter pipe, you could also go to a "cerges reactor" which is just a clear whole-house filter with no cannister (Gerry D has a big thread on it). A filter housing may be cheaper and easier than buying clear PVC--its all the same, just create dwell time with the gas and water.
 
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Whiskey

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Jun 14, 2010
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I built a rex grigg type reactor without them once and found that the pump pushed the CO2 straight through the reactor to some degree giving me some CO2 mist in the tank. I didn't like this. Ever since then I've been using the bioballs and I haven't had that problem once. I think it slows the flow down in the center of the reactor making it more difficult to push the bubbles straight through.


Whiskey
 

rjordan393

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Mar 5, 2013
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I am building a 3 inch reactor and hopefully the investment pays off. I am waiting for some parts to finish it. Should have it in service by 12/17. My experience with physics tells me that I will get more dwell time and turbulence to further dissolve the CO2 bubbles.
 

Tom Barr

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I've used those, they help break up the currents and some of the bubble gaps that form. They do not clog either........that's one of the main features/reasons to bother with them.
 

Squidly

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I've previously tried the AquaMedic and a DIY reactor(s) based on a mix of Tom and Rex's plans, but found none were sufficient to manage properly the amount of Co2 I needed for a 100g tank. I'd tried with bioballs and without - and it was always a noisy affair. Because my built in overflow and sump are limited, I cannot install a simple bypass as Tom recommends with those who have large sumps. For a long while I just ran a NW pump inline behind a Nu-Clear canister filter (never clogs or slows down). This worked far better than the reactors, but a lot of Co2 just swirled around the tank and was wasted. Plus all those bubbles weren't pleasant to look at and I continually had issues with BBA etc.


I recently took the plunge and purchased a 20" filter housing w/1" I/O (Cerges) and wished I'd started out with it. Attached to it, I have a 700gph pump running full blast and have no (0) bubbles going into my tank. In my experience, the Cerges reactor is far more efficient than the NW (or other smaller reactors) have been. Some have tried to push Co2 from NW pumps to the Cerges but had problems with mist entering the tank and have tried increasing the dwell time in a variety of ways to resolve this. I discovered that it is far more efficient to simply connect the Co2 inline directly and let the pump run. This has worked perfectly for me. No bubbles in the tank, no build up in the reactor -- and no gurgling!


I have tried bio-balls to chomp up the bubbles, but found them noisy until I mixed two sizes together which quelled the noise to a large extent. Some had suggested using 'scrubbies' which I also tried, but found they restricted the flow and likely would eventually need cleaning. I finally took everything out and find that the Cerges runs perfectly and there is no need for anything to mince the bubbles up (I've since ordered the small floating bio media for moving bed filters for kicks).


It's a bit of $$ up front (you pay more for the AquaMedic), but it will be the last reactor you'll ever have to waste your money on!
 

Christophe

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I just put in a 4" x 20" PVC Grigg reactor (no Bio-balls or anything) because my 2" x 20" was not dissolving gas well enough. I drive it with a Sicce 1.0, probably 150GPH considering the head loss, returning to the sump. This GREATLY reduced the number and size of the bubbles that do make it to the tank.


Dwell time varies by the cross-sectional area of the reactor. Grigg vs Cerges doesn't matter -- a Grigg is just a Cerges with the return tube outside its body.


- - - Updated - - -


I just put in a 4" x 20" PVC Grigg reactor (no Bio-balls or anything) because my 2" x 20" was not dissolving gas well enough. I drive it with a Sicce 1.0, probably 150GPH considering the head loss, returning to the sump. This GREATLY reduced the number and size of the bubbles that do make it to the tank.


Dwell time varies by the cross-sectional area of the reactor. Grigg vs Cerges doesn't matter -- a Grigg is just a Cerges with the return tube outside its body.
 

Whiskey

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Jun 14, 2010
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My reactor is also 4", I use it on a 75G tank, but I push close to 700GPH through it using a Iwkia pump and never have a single bubble make it through. It is full to the top with Bioballs.


I also had a 3" one full of bioballs, I pushed 300 or so gph through that one, it also never had a single bubble come out the bottom.


With my 4" one I was able to drop the PH from almost 8 to around 5 in under an hour when my regulator blew out, this is with a 75G tank. That sucked to say the least but it tells me that the reactor is sufficantly oversized. My KH is 7 BTW


Whiskey
 

rjordan393

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Mar 5, 2013
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Levittown, Pa.
I placed my 3 inch reactor in service and I got the same result. I have not seen one bubble leave it. Its 4 feet long and the CO2 count is approximately 5 bps. So adding bio-balls and the extra dwell time resulted in the improvement. What is not clear, is whether the length is over kill. However, I get a strong flow at the tank discharge which I did not expect. I wonder if the weight of the water in the reactor has anything to do with this.