CO2 Reactor Lesson Learned

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Aquarium Advice Addict
Apr 4, 2014
Smithfield, Va.
I built a Rex Grigg style CO2 reactor over the Thanksgiving holiday. My tap water is about 7.6 PH. Diffusing CO2 with a ceramic diffuser from GLA at about 4 BPS I was about neutral (7.0). With the CO2 reactor I am about 6.6. Lesson learned: Reactors really work and they are efficient; therefore, reduce the CO2 to 1-2 BPS.

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I am planning on building one this week. What directions did you use? At the other forum all the pictures etc seem to be old and removed.

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Thanks. I have been debating if I want my top to be a straight bart and then drilling a hole for the CO2 versus a 90 degree. I assumed a 90 degree would reduce flow a bit but then again it seems like it would create more turbulence so that has to help.

Did you use clear PVC? I can't find it anywhere locally. One plumbing supply said they can get it for $10 a foot with a minimum of 10 feet.

Did you use bio balls? I wasn't going to because I don't have any and rather not buy some! I believe the original Rex Griggs reactor suggested they were not needed.
I used to order pond supplies from aquatic eco-systems and they carried clear PVC. I just did a search for it (website changed drastically from what I remember) and found some clear plastic rigid tubing. Not sure if it is exactly what you are looking for or if the price is better or worse. Happy hunting!

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I used a Python gravel cleaner attachment. I found a bushing that fit "perfectly". I did see some clear PVC on EE Bay, but honestly the clear is merely cosmetic and not needed. The reaction takes place in the first 6 inches anyway. Plus, with a reactor, you only need 1-2 BPS.

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I've seen a gravel vac used for this while researching DIY builds. Clear PVC is costly. I just went from 3 to 5 bps with my current setup. I'd like to increase the efficiency and lower the bps in the process. Thanks for the post.

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I used bio balls.. useless?? Maybe... in my reactor forever?? Yup...

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LOL Brookster. yeah, I watched a few Youtube videos for guidance. I have seen absolutely no bubbles exiting as of yet.
im sure it wouldn't have mattered either way.. if anything.. they will keep bouncing around the chamber to dissuade crap from accumulating on the sides.. hmmmmm

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I have decided to build the cerger version. The additional cost is really just the 18 filter at home depot otherwise most connections are the same.

I got a fluval 406 to power it so we will see how it turns out this weekend.

Hopefully it helps my tank since j got a canister filter just for the purpose of the inline reactor. Well that and better water movement.

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Yeah, cool. I am also building a Cerges for another tank. I am just waiting on Menards to ship the filter to me.

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I too built a griggs style reactor. I just used schedule 40 pvc not clear. It was more of a test to see if it would work and I was sick and tired of my tank looking like 7up. I was using my powerhead as my diffuser. Now there are no co2 bubbles at all. I had similar results to dcutl002 and had to back down my bps.
My next creation for my 55 gallon. The epoxy for the CO2 is still curing. ImageUploadedByTapatalk1417833962.535148.jpgImageUploadedByTapatalk1417833994.763029.jpg. And then for my last tank...ImageUploadedByTapatalk1417834062.726637.jpg. I purchased this from Menards for 14 dollars plus shipping.ImageUploadedByTapatalk1417834141.016374.jpg

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I just got the standard white one from Home Depot. The 2-3 week ship time on Menards site scared me away a little.

ImageUploadedByAquarium Advice1417886651.236482.jpg

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Hardest part now is getting it in the cabinet and avoiding kinking the lines.

I assume extra tubing to make a circle will hurt flow a bit.

Was going to do a straight shot to the filter but then it won't leave me any slack to take the filter piping out which I figured could be an issue.

ImageUploadedByAquarium Advice1417900341.494859.jpg

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Maybe a little bit.. wouldn't think it to be too dramatic though.

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That curl will have a minuscule effect on your flow at best. You're good.

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