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Building a Speece cone CO2 reactor

15K views 77 replies 12 participants last post by  rajdude 
#1 · (Edited)
Hi folks!
I have been researching all the various methods of dissolving CO2 in our tanks. The most interesting one I have seen is the Speece cone. However almost no one in our hobby talks about it and even less people build it. I would like to try and build one. Here is what I have found so far.


First, what is a Speece cone?
Well, it is a inverted cone type design which is used commercially. check it out:


and




Here is a good video explanation:




And they make them REALLY big, see here:
https://www.army.mil/article/179827/speece_cones_delivered_to_shep_mitigation_site


I was wondering if we can make one for CO2. I did find one guy here talking and building a Speece-Cerges hybrid:

i shoved a Perrier bottles in mines

DIY Ozone Cone/ Cerges Hybrid - YouTube



if the co2 is gonna get trapped anywhere it's gonna be the Perrier bottle, the flow coming in from the pump is just gonna keep pounding it til it's saturated.

That sure is an simple build solution. Anyone else tried this?

I was wondering what could be used to make it without using a filter housing. And if filter housing is the only or easily available solution, what can be used inside it, something conical, like a plastic flask with its bottom cut off? I found some on eBay, but most are white, not clear.

I do not like the idea of back pressure needed for Cerges. It will restrict flow of my canister. I think bypass plumbing would be a good way to maintain flow and be able to tune the Speece cone.

Anyway, for now, here is what I would like to do:
  1. Get a filter housing which has big enough connectors. Is 3/4" good enough or we need 1"?
  2. Get a conical flask, cut off its bottom, install it in the middle
  3. Build a bypass, something like the one below, but with less elbows, if possible.

What do you say?



Best I can offer on this subject...

 
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#4 ·
in-line diffuser

I have been thinking of using an in-line diffuser just like Mr. Keating does. But I read that it does not work with a Cerges reactor, too many micro bubbles escape. Just read that the bubbles are doing ok in his style reactor :grin2:
Even better!


With the reactor I'm using, all bubble get dissolved into the water column before they exit the reactor. ........snip....

The only problem is........I have only around 14" vertical space in my cabinet :frown2:
 
#7 · (Edited)
Yeah, I hear you.....that could be my only option........unless I put the Speece reactor in the adjacent room, where I am planning to put the CO2 equipment, anyway. Longer hoses from the canister filter will be needed...but sure how much that will slow down the flow, though.


I do have a couple of concerns about Cerges style reactors, though:

  1. Most people say that they slow down the flow.
  2. Need pressure buildup inside it, using valves.

I got a Fluval G6, rated at 265 GPH with filter media, head and hoses factored in (its pump is rated at 665 GPH). I really should test it out. Tank is a 65 gallon. I am not going with a sump at this time. Maybe with the next, bigger tank with bigger stand where all this could fit inside. My tank right now is very plain vanilla, started it a month back... I have a mud room to the right side of that filter sitting on the floor. Planning to punch a hole through the wall, behind that canister...for CO2 pipe. Got some other ideas also....but that is now going OT. Gotta start another thread for that.










Bump: So question.......
Can we slow down the water flow through Cerges and let most of the water flow through the bypass...or are those valves intended to increase water pressure inside Cerges? I am confused....I have read that the latter is true.


I am trying to keep water flow intact.


snip
Kind of what I discovered is that its easy to overthink co2 reactors but the reality is that any reactor with slowed water movement is going to work and its us hobbyists that tend to mess them up by adding doodads on.
 
#6 ·
I didn't know these were called Speece cones. I think I was previously searching for them under something like gas cone or some such. Anyway I tried to build one out of pvc a year back. Here is what mine looked like:



As you can see its quite huge. I used it in some experiments where I tried to dissolve room air into the water, I wanted complete dissolution but couldn't make it work. I eventually cut it apart to make a smaller modified rex griggs style reactor with a bypass.



I recently added a valve on the bypass because apparently that is where it actually needs to be.

Kind of what I discovered is that its easy to overthink co2 reactors but the reality is that any reactor with slowed water movement is going to work and its us hobbyists that tend to mess them up by adding doodads on.
 
#8 ·
As you can see its quite huge. I used it in some experiments where I tried to dissolve room air into the water, I wanted complete dissolution but couldn't make it work. I eventually cut it apart to make a smaller modified rex griggs style reactor with a bypass. .
Your reactor design wasn't the issue with incomplete dissolution, the problem was that air is 78% nitrogen and nitrogen is only slightly soluble in water. If you used CO2 only you would most likely would of had complete dissolution.
 
#9 ·
@minorhero was going to mention about the valve on the by-pass but you already noted that.
Something of interest, being on the subject of the bypass valve, in my original setup I was using a Marineland canister filter. With it's filtered flow of XXX gallons per hour, having the bypass valve at 60-70% shut seems to be about right for dissolving the bubbles before they left the reactor. I eventually upgraded to the AquaTOP CF500 canister and found the water flow thru the reactor to be too fast. With the bypass valve set to 40-50% shut the flow thru the reactor was again correct.
Recently I installed a Fluval FX4 canister filter. After a little tinkering I realized there was alot more flow. The bypass valve is now at about 10-15% shut.

A bypass valve on the Speece cone would likely be of the same value - optimizing flow within the reactor and allowing the excess flow to bypass.
 
#11 ·
@rajdude - one of the biggest problems I have found with the Cerges reactors is not the basic design, but the inlet/outlet of the water filter being converted to a reactor.
If you happen to stop at a Menards/Lowes/Home Depot and look at the actual whole house filters you will note the inlet/outlet thread sizes range from 1/2" to 3/4" pipe thread. But the actual hole where the water goes into is typically alot smaller.
I found a 3M brand whole house filter (standard 10" tall) that uses 3/4" pipe thread and the hole where the water goes is atleast 1/2" to maybe 5/8" in dia - much better for water flow!

Like I stated above - the by-pass valve helps retain overall GPH water flow of the system.
As for pressure, honestly I have found putting the reactor as close to the floor (more head pressure from the tank above) does a better job at dissolving bubbles as opposed to forcing the water from the canister filter into the reactor (valve on the reactor output).

Bump: https://www.thermofisher.com/order/catalog/product/DS4101-0500#/DS4101-0500
Hmmm, wonder how big a 1,700ml (58oz) flask really is? About 1/2 gallon. Might be big enough for a 60g tank :)
 
#13 ·
@rajdude - one of the biggest problems I have found with the Cerges reactors is not the basic design, but the inlet/outlet of the water filter being converted to a reactor.

If you happen to stop at a Menards/Lowes/Home Depot and look at the actual whole house filters you will note the inlet/outlet thread sizes range from 1/2" to 3/4" pipe thread. But the actual hole where the water goes into is typically alot smaller.

I found a 3M brand whole house filter (standard 10" tall) that uses 3/4" pipe thread and the hole where the water goes is atleast 1/2" to maybe 5/8" in dia - much better for water flow!



Like I stated above - the by-pass valve helps retain overall GPH water flow of the system.

As for pressure, honestly I have found putting the reactor as close to the floor (more head pressure from the tank above) does a better job at dissolving bubbles as opposed to forcing the water from the canister filter into the reactor (valve on the reactor output).

Bump: https://www.thermofisher.com/order/catalog/product/DS4101-0500#/DS4101-0500

Hmmm, wonder how big a 1,700ml (58oz) flask really is? About 1/2 gallon. Might be big enough for a 60g tank :)
Thanks for the tips [emoji4]

Sent from my H8314 using Tapatalk
 
#14 ·
I'm an extrusion blow molding technician at Thermo Fisher in Rochester, I actually make these filtering flasks. There made from polypropylene that is somewhat opaque, it would be difficult to see clear liquid inside. The barbed tip has a rather small ID, maybe a quarter of an inch, so it would be quite restrictive. For a very clear cone shaped bottle, the 2000ml seperatory funnel made from Teflon (FEP) comes to mind, however, they run 6 or 700 each. But they are inert to basically any acid or base and have a working temp from -100 to 250 degrees.
 
#43 ·
Ken, clear PVC vinyl pipe is not the same thing as clear PVC pipe, correct?
Yesterday, I went to Home Depot, because their website shows they have this:
https://www.homedepot.com/p/Everbil...bing-HKP001-PVC017/303132517?modalType=drawer


I looked at it and realized:
1. it is flexible
2. it does not fit into any slip fittings, OD is not compatible
3. probably cannot be joined using the cement


So I guess I will have to order what you suggested. Was hoping I won't have to wait and also, pay shipping :frown2:
 
#18 ·
That 1000 ml is definitely mislabeled, it's made from petg, not polypropylene, they're made on bekum 7. It's also not meant to be autoclaved as they're a single use sterile bottle used more in biotech for cell cultures and whatnot. We also make a 2000ml in the same style, baffled bottom and a regular bottom as well.
 
#22 · (Edited)

Attachments

#24 ·
Hold me over?

Until I get a proper Speece cone built, if there a "hold me over" option? I could buy an inline diffuser...but they are like 40 bucks, and that money could go waste if I don't use it in the long run.

Can I just use an air diffuser, for a week or so? I have a few lying around unused.

Sent from my H8314 using Tapatalk
 
#25 ·
Or just build a Rex Grigg for like $20 and be done with it. It's the same principle just different shape but the rate of CO2 disolved into the water is likely very close to the same as the Speece. Certainly close enough that IMO it's not worth the extra money and trouble of finding the parts to build the Speece reactor. I mean you'd think that if the Speece was head and tails better then the Rex Grigg or Cerges, other people would be using them and at least one or two companies would be making and selling them. Of course if you are doing it just to try something different and to have fun...by all means...go for it. Otherwise, I don't see the point.
 
#26 ·
hmmmmm, but

Well, yes I could make a Griggs/Cerges and call it a say but like I said earlier, I have a few concerns:

  1. Low flow
  2. Price
My flow concerns could be alleviated by making a good bypass system, but I think by the time I add the Y fittings, bypass valves, clamps, barb fittings, glue, primer......I am 99% it will not be just $20 bucks. Probably should stop at Lowes today to check out the prices.

By the way: I like this bypass design with Y fittings instead of the Tee and the elbows most other designs use. We should minimize the number of right angle turns to maintain the flow.


You can build a Cerge's Reactor for $20.55. The filter housing is $13 on Amazon and the other PVC parts can be found online as well. I was previously using an inline atomizer which worked fine, but my tank always looked cloudy from co2 bubbles. The reactor was 100% efficient and the water was clear. I always recommend a reactor.

Here is a pic of my old reactor.
Or just build a Rex Grigg for like $20 and be done with it. It's the same principle just different shape but the rate of CO2 disolved into the water is likely very close to the same as the Speece. Certainly close enough that IMO it's not worth the extra money and trouble of finding the parts to build the Speece reactor. I mean you'd think that if the Speece was head and tails better then the Rex Grigg or Cerges, other people would be using them and at least one or two companies would be making and selling them. Of course if you are doing it just to try something different and to have fun...by all means...go for it. Otherwise, I don't see the point.
 
#32 ·
Well, yes I could make a Griggs/Cerges and call it a say but like I said earlier, I have a few concerns:

  1. Low flow
  2. Price
My flow concerns could be alleviated by making a good bypass system, but I think by the time I add the Y fittings, bypass valves, clamps, barb fittings, glue, primer......I am 99% it will not be just $20 bucks. Probably should stop at Lowes today to check out the prices.

By the way: I like this bypass design with Y fittings instead of the Tee and the elbows most other designs use. We should minimize the number of right angle turns to maintain the flow.
The $20.55 is not including the true wyes or the ball valves, it is just the required parts for the reactor. I can make a list with all the websites if you want.
 
#27 ·
The flow through my Rex Grigg is just fine. If there's a major concern, bump up the size of your filter. I mean yeah...I'm sure I lost some flow, but not enough to cause me any concern. I'm using an Ehiem Classic 350 on a 32g tank.

Price...it costs about $20 to build one. Less if you know someone that has the primer/glue and maybe a scrap of pvc pipe so that the only thing you need to buy would be the fittings.
 
#28 ·
Two big points that I might add. One is that any fitting we add that goes inside the tubing does reduce flow. This is true of Cerge's, Grigg's or any other item. Easy to see why when we look at a 3/4 inch fitting and see that the walls of that fitting are something like 1/8 inch on each side of the opening, so the inside opening of a 3/4 inch fitting is more 1/2 inch! Water flow can often look very much like traffic flow. when the area is reduced the flow slows down and it will also be slowed by sharp corners like 90 degree elbows. Cause turbulence or a loss of lanes and traffic slows down. Works the same with low pressure water.
Then there was mention of going with one of the "standard" reactors but not adding too many bells and whistles which tend to screw up the operation.
When things work so well that they are as accepted as the Grigg's or Cerge's, they become very much like the wheel idea and it takes a mighty fine idea to improve the overall operation of either.
When something works great, why try to improve it if not just simply as a hobby when bored?
 
#29 ·
Tinkering is awesome. That's how we get great new things or improve on old ideas. But like you said PlantedRich, Grigg's or Cerges being the wheel...I'm not sure a Speece is enough improvement (if any) to reinvent it. But again...if playing and experimenting is your thing rajdude...by all means...I just don't think it's worth it from my perspective. It's not a new idea and since the Speece has been around a while...if it was better by enough margin it would be more popular. But it could also just simply be that parts are not readily available or not available for cheap whereas the Grigg's and Cerges can be made from parts sourced at your local big box hardware store for way less than the cost that you'd put out for the Speece. I know it would be added cost over the long run, but if I were you, I'd build a Grigg (or Cerges) and run that and if you are so inclined, in the mean time start sourcing parts to play around with building a Speece style reactor. That way if that idea doesn't pan out, you have the tried and true Grigg's/Cerges and if the new idea works out, you either have a back up or you could easily sell the Grigg's/Cerges to someone else. People ask about buying them often enough you should be able to easily sell it for at least your cost in parts.
 
#30 ·
Wow good find on the flask!! Search terms are so freaking awesome. When I was trying to build my reactor I couldn't find anything cheaper then a few hundred dollars. But I also didn't know to call it a flask. I was searching for things like clear cones and such.

Did some e bay searching and found a company selling:

"Nalgene™ Single-Use PETG Erlenmeyer Flasks with Baffled Bottom: Sterile VENTED"

They have a 2000 ml size that cost $11.13 shipped with tax. For that price I will cheerfully experiment. I will need a means of attaching it to the rest of my plumbing. This means I need to drill the bottom, install a bulkhead of some kind, and probably do something similar at the top as well. Meanwhile I will need to create a bypass for the rest of my water since its not going to all be able to run through this thing. Anyone know a cheap place online to buy pvc parts like bulkheads and elbows etc?
 
#33 · (Edited)
good find!

Whoa! good find! Thanks! But it says baffled bottom, maybe we'll need to drill on the side?



When I looked for yours another one popped up under it
item # 162440034162
Nalgene PETG Sterile Plain-Bottom Erlenmeyer Flask with Vented Closure
$39.99 free shipping
Expensive, but hey! it is 2800 ml! Measures 273.1mm high, with an outside diameter of 161.5mm at the widest part of the base and an inside diameter of 35.6mm at the neck


:grin2:





I wish I knew where to buy PVC stuff online for cheap, other than eBay. Home Depot - Lowes may have the bulkhead barb fitting we need for this.

Here is one which may work... eBay item number: 174244707664 for $7.38 for two, shipped :nerd:



So for eighteen and a half dollars....total its a good test! Ha ha





Wow good find on the flask!! Search terms are so freaking awesome. When I was trying to build my reactor I couldn't find anything cheaper then a few hundred dollars. But I also didn't know to call it a flask. I was searching for things like clear cones and such.

Did some e bay searching and found a company selling:

"Nalgene™ Single-Use PETG Erlenmeyer Flasks with Baffled Bottom: Sterile VENTED"

They have a 2000 ml size that cost $11.13 shipped with tax. For that price I will cheerfully experiment. I will need a means of attaching it to the rest of my plumbing. This means I need to drill the bottom, install a bulkhead of some kind, and probably do something similar at the top as well. Meanwhile I will need to create a bypass for the rest of my water since its not going to all be able to run through this thing. Anyone know a cheap place online to buy pvc parts like bulkheads and elbows etc?
 
#36 ·
Thanks for your advice, @Nubster, @PlantedRich and others. Yes I am tinkering... but not really trying to re-invent the wheel.

The simplest way to tinker, and test....for me here, is do do what @SingAlongWithTsing did (shown in the first post in this thread)....build a cerges and run it in reverse, with a conical bottle in the center.

Although the flask mentioned above is starting to sound very attractive!

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#37 ·
10" filter housing with 3/4" ports - Amazon ($13)
1/4" MPT 3/16" barb - HoseWarehouse ($1.69)
3/4" MPT to 1/4" FPT reducer bushing - PVC Fittings Online ($2.02)
3/4" FPT tee - PVC Fittings Online - ($1.37)
3/4" MPT x 1" barb - FlexPVC ($1.70 each, need 2)
3/4" MPT nipple - PVC Fittings Online ($0.76)

You would need teflon tape for all the threaded parts, and a portion of 1" tubing to connect to the inside of the filter housing (the picture I posted it is the green tubing).
 
#39 ·
I was worried at first about the amount of flow going through the reactor. I could've reduced flow on the bypass to increase flow into reactor, or reduce flow into reactor and more into the bypass. After setting the whole thing up it worked fine with both lanes wide open. I could've gotten away with having no valves.
 
#45 · (Edited)
So I also need some recommendation please, on what pipe/hose to buy.


I need around 20 feet, 16 mm (or 5/8") ID. From canister to reactor and back to tank. And for bypass also. Also thinking of moving the canister to an adjacent room, where I am planning to have the CO2 tank, reactor etc.

Options so far are:


  1. I looked at the clear vinyl hoses at Home Depot. They are very easy to kink so not too keen on those.
  2. I saw braided versions. A little expensive there, $20 for a 10' length.
  3. On flexpvc.com I see their flexible hoses...but they say those are NOT for potable water....meaning not good for aquarium use also.


In your thread, I see some flexible pipe you are using, visible in your shed photos. What is that?
Is its interior smooth or corrugated?

Last Q: does it makes sense to just buy all PVC fittings from flexpvc?
 
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