Horizontal CO2 Reactor - Yugang 鱼缸 Reactor

[Yugang]

A detailed thread can be found on UKAPS, linked with the kind permission from Scapecrunch forum moderators #1

Sending my to UKAPS admins for deleting this thread. A tribute to innovation and progress in the hobby. I have moved on, and am not that passionate anymore to test and share new ideas, but I like to avoid that so much work over 2 years gets lost. When I have more time, I will scan my notes and post here in ScapeCrunch what is missing after deletion. Unfortunately I will not be able to recover the many questions and suggestions from UKAPS members, which was probably the most valuable and most fun to read.

Note: For probably obvious reasons I have decided a year ago to take it easy and no longer explore and share new technology. In a post that has also been deleted on the other forum I have hinted that there are possibilities to fully rethink CO2 injection and stabilisation for the planted aquarium. Forget expensive precision CO2 regulators, diffusers, the risks of KH swings on pH as a proxy for CO2, risks of malfunctions in pH controller. We can have an entirely new CO2 injection mechanism, electronically/computer controlled, low cost and perfectly safe, unparalleled CO2 stability, with the possibility to even measure/estimate plants CO2 uptake during the lights on period. Innovative vendors, or anyone with a serious interest to develop and bring new functionality to the hobby, let me know in a PM and we can explore how to take it further.

 

[BigWave]

WOW. WTF. No wonder this hobby goes no where!!! Seriously makes me not even want to help anyone anymore and just do me. All the forums and even some facebook groups are serioulsly moderating information.

 

[Yugang]

WOW. WTF. No wonder this hobby goes no where!!! Seriously makes me not even want to help anyone anymore and just do me. All the forums and even some facebook groups are serioulsly moderating information.

IMO we are together here to keep ScapeCrunch a good place, and so far I am very happy how this forum is developing.

The person who I admire most for his huge contributions to this hobby once wrote to me (paraphrased, as my PM's got deleted) "Lack off progress in our hobby is not a science issue, it is a people issue". Wise words.

 

[Unexpected]

Yeah, it’s terribly unfortunate. Good thing we have ScapeCrunch. We just keep doing our thing and eventually people will get curious and come. I mean, we have champions and 2nd place winners here .

 

[Yugang]

I mean, we have champions and 2nd place winners here .

And at least 3 previously banned from other fora

 

[toofewfish]

Well hopefully you will stay around and contribute here. Your ideas are always interesting to me. I built a horizontal reactor for my 150 gal after reading thru your post and it works great. No fuss, always consistent.

Don't get discouraged, there's good people here that want the hobby to thrive.

 

[Unexpected]

Well hopefully you will stay around and contribute here. Your ideas are always interesting to me. I built a horizontal reactor for my 150 gal after reading thru your post and it works great. No fuss, always consistent.

Don't get discouraged, there's good people here that want the hobby to thrive.

100%, Yugang, work your magic here! Seriously.

 

[JohnLaPaz]

i believe the reason why Yugang was banned from ukaps forum it's just because that way to diffuse co2 in the tank is effective and really cheap compared to the "bubbles way" and all the expensive co2 stuffs, and people in the co2 bussiness know that.

i move here after the ban of yugang to ukaps and the "spraybar" thread.

i have a ADA 45p, and the co2 is passive diffusion via the topper from Dennerle.

i use yeast to produce co2. and the topper is currently running near the inlet of the filter for a best diffusion in the tank. Now, i’m just using one oh these toppers.

here some pictures from the beginning of the tank to today, after a few changes on the hardscape and some plants.

 

[Yugang]

I built a horizontal reactor for my 150 gal after reading thru your post and it works great. No fuss, always consistent.

This is great to hear. Have you been using the 17.7 ratio, and have you also been targeting 1.5 pH drop?

I am using my reactor in overflow mode, and have reduced the size by nearly 50% as I start to believe that 1.0-1.2 pH drop is probably nearly as good as 1.5-1.6 as long as we keep it all stable. 0.3 pH difference corresponds to about 50% CO2 ppm, and thus significant savings as well as probably some comfort for fish, shrimp (and perhaps even microorganisms). Also, I can afford a bit more percentage overflow (and thus improved stability of injection ) without sacrificing too much in CO2 losses.

It would be nice if you could share some more build and use data.

Is anyone using the reactor for a 1.0 pH drop? By adjusting regulator / pH controller, or also with modifications of the reactor capacity from the original 17.7 design rule?

 

[Yugang]

A quick update, as I continue to learn from using the reactor in my tank.

My favourite mode of operation is the overflow mode

... which means that I always use the reactor at its maximum capacity and that it is the reactor geometry that stabilises CO2. As I used the original 17.7 ratio for calculating the dimensions, my pH drop exceeded 1.5, which actually I found a bit too much.

I decided to reduce my reactor power a lot, so that I now have a nice lime green drop checker.

Original dimensions (using 17.7 ratio for 1.5-1.6 pH drop):



I reduced the size. It helps that I did not use glue for the transparent acrylic to pvc, but teflon tape and can easily disassemble and assemble back again with adjusted dimensions.



I fully understand that all users so far use the reactor in a more conventional manner, i.e. adjusting the CO2 flow with a precision CO2 needle valve or using a pH/CO2 controller. I believe it is only a matter of time for others to start using overflow mode as I am doing. I don't care anymore about the precision or stability of my CO2 regulator, I am not using a pH/CO2 controller anymore, and I don't even see why I would buy a new pH probe (it broke down a couple of months ago). With overflow mode, and especially now that I understand much better how it works, CO2 has become so easy and reliable for me. But we need a slightly different approach, and know how to set it up and verify if everything is ok.

I have now three different checks to verify if I inject enough CO2 in my reactor:

1. Having a transparent tube, I can see the bubbles injected in the reactor. I know the bubble / second for my maximum reactor capacity, and target 5-10% higher to make sure overflow mode is optimised. For this I would need to make a 10 seconds video, and obviously I don't want to do that too often.
2. When the reactor works well in overflow mode, I will have some small bubbles escaping every now and then through the spray bar in my tank. This is a very easy verification that injection is good, and I check that with observing my spray bar for half a minute or so, several times per week. My CO2 regulator is not perfectly stable, so if I see no bubbles escaping at all, I will give it a bit more flow without caring too much about precision.
3. As I described in an earlier post, the same physics that lets CO2 absorb in the water will cause some other gases to build up in the reactor. This happens for bubble reactors, or horizontal reactors, in fact at any interface between pure CO2 and water. In my post #156 I calculated how much 'air' will build up as a function of CO2 flow, and I can see this air early in the morning in the reactor before CO2 turns on. If I see really little air, it means that my reactor the previous day has been purging very efficiently, and that I have a really good CO2 flow or perhaps even too much flow and unnecessarily waste some CO2. If I see too much air in the morning, I'd better increase my CO2 flow a bit. I can imagine that this is still a bit confusing to read, and I am happy to further elaborate in follow up posts. I use this method just when I am curious if everything is ok, and definetely not as regular as the previous 2 methods mentioned.

This is my reactor early this morning. I see very little air in the top, and know that everything if fine.



I believe in a few years time, many if not most will use overflow mode and enjoy the savings on expensive CO2 components that are now still necessary for CO2 stability. Anyone who wants to give it a try, do not hesitate to reach out to me with PM, so that I can help as much as I can until we are all confident it works well.

 

[Unexpected]

How many gallons is your tank @Yugang?

 

[Yugang]

How many gallons is your tank @Yugang?

About 50 gallons.

 

[Unexpected]

About 50 gallons.

And how much of a drop with the shorter length?
And what’s the time from CO2 on to peak CO2?

 

[Yugang]

And how much of a drop with the shorter length?

Lime green drop checker, probably around 1.1 or 1.2. Don’t have a pH probe anymore, don’t see a need to buy a new one, and in fact care more about stability than my exact CO2 ppm value.

 

[Unexpected]

Lime green drop checker, probably around 1.1. Don’t have a pH probe anymore, and in fact care more about stability than my exact ppm value.

So only a .4 difference with what looks to be more than a 50% reduction in reactor length.

 

[Yugang]

So only a .4 difference with what looks to be more than a 50% reduction in reactor length.

This can be easily calculated, and that’s what I did before cutting my pipe in two. The pH / CO2 ppm table is logarithmic, a 0.3 drop in pH corresponds to 50% increase of CO2 ppm. Reduce the reactor absorbtion power by 50% will give around 50% reduction in stabilised CO2 ppm and hence around 0.3 pH drop reduction from the 1.5 where I started.

So indeed in overflow mode we can calculate reactors for the pH drop that we target for, and then the best thing for stability is to launch and forget and let the reactor do its thing for a few years.

Note: anyone who likes to finetune the reactors power and CO2 ppm, without cutting or changing the tube, may consider to let a piece of styrofoam float in the reactor. The foam will reduce the effective reactor CO2/water surface area and therefore the reactor injection rate. I am personally not a fan of this, but some may like the idea. Obviously this only applies to overflow mode.

 

[Burr740]

Cant believe they deleted your thread, wtf..

Been meaning to report, I had a 3"x28" behemoth running on a 75 gal. It had to be that big because I was just shooting co2 into the canister line just before the reactor. It wasnt entering inside in the middle like a true griggs should be. Anyway after reading about this design I just changed the tubing to accommodate for the new different distances and laid that sucker horizontally on its side.

I thought I was getting good dissolution before, no visible bubbles, but with it horizontal Im getting the same 1.3-1.4 ph drop with less co2. I dont have a flow meter on this tank so cant say exaclty how much less, but just going by the steady stream of bubbles before and after Id say 20-30%.

So even though I didnt get at all technical about it I can say for certain that having it horizontal is the way to go. I'll get around to doing the other 7 tanks I have with reactors eventually

 

[Yugang]

So even though I didnt get at all technical about it I can say for certain that having it horizontal is the way to go. I'll get around to doing the other 7 tanks I have with reactors eventually

I remember you asking back in May @Burr740 , very happy that it works so well for you. I'm not asked that often anymore for help with calculations, which tells me that we're on the right path.

It would be great if I could convince you to configure one of your 7 tanks with a reactor in overflow mode, as I believe that several will follow the example of a very experienced scaper like yourself if you show that it works. My hope is that with horizontal reactors in overflow mode proven to work, debugged and widely accepted, we have successfully eliminated a bit of unnecessary complexity and cost for high tech tanks.

 

[JohnLaPaz]

@Yugang so, now you are operating with a ratio of 35,4 to obtain 1 ph drop. Or we need to know other details ?
how much is your KH ?

 

[Yugang]

@Yugang so, now you are operating with a ratio of 35,4 to obtain 1 ph drop. Or we need to know other details ?
how much is your KH ?

Now at home, I checked my notes and double checked my reactor, I am now at a ratio of 40 to be more precise.

Drop checker lime green, but until I decide to buy a new pH probe I can't tell precisely what my pH drop is. As far as CO2 is concerned, I have gone minimalistic, as I don't see the point (at least for my own tank) of doing more measurements and my tank is more stable than ever. Using overflow mode, I am happy with my pH drop, whatever it exactly may be, and my motto for CO2 is now "launch and forget" - no need to measure, monitor or adjust anymore and just I focus on the other things that are important for the tank.

My advice would be, when building the reactor for overflow mode, anticipate that you may want to disassemble to adjust the size a bit until you're perfectly happy with your pH drop. Obviously the ratio's that I estimated (like the original 17.7 and now my current 40) are all based on my tank and other tanks may have some different surface agitation and outgassing and the ratio's may be different from mine. The reason that nobody complained about the 17.7 so far is that it gives a reactor that is for nearly every tank overpowered and when CO2 is regulated with needle valve or controller always good enough for any targeted pH drop. I use overflow mode, and then the reactor geometry will be the sole driver of CO2 injection.

In summary @JohnLaPaz if you use precision CO2 regulator or pH controller you may want a really strong reactor for the fastest ramp up and you may want to stick with the 17.7 ratio. In overflow mode, you may want to have a less powerful reactor so that fish are less stressed at pH drops exceeding 1.5.

My KH is around 2 to 3, depending on the season in HK.