Horizontal CO2 Reactor - Yugang 鱼缸 Reactor

[Unexpected]

After calibration and more time to test, I reached a 1.3 pH drop on this tank. Again, a very crude test and I need some parts to optimize the test conditions.

My sump level was too low causing the returning water to basically rain inside the sock chamber. This is the noise you can hear in the video above. This problem has been solved and I’m anticipating by Saturday having all the parts I need to have an accurate test.

 

[HardeeParty]

Just these initial test results are astounding.

I dont get it though. You got booted from ‘theforumthatshallnotbementioned’ for suggesting you turn a 1.0 beta version of a Rex Griggs reactor on its side and do some math? Do they like counting bubbles that much?

 

[LMuhlen]

I tried to put together my compact reactor, but had some trouble making the holes on the sides. The plastic is brittle and when trying to open a whole and then enlarging it, it formed some cracks. I also had trouble closing the box after installing the connections, the tabs for closing it are on the length side, where the connections are. I did manage to close it by cutting some excess plastic from the tabs, but if I decide to buy a new piece, I'll try to avoid the ones with tabs on the length.

In any case, I set it up for a first leakage test and, as expected, it leaked on the cracks that formed. But apparently the connections didn't leak, so that is good. I'll try to seal the cracks, but if I can't, I'll have to buy a new one and think of a better way to drill the holes.

 

[Yugang]

I tried to put together my compact reactor, but had some trouble making the holes on the sides. The plastic is brittle and when trying to open a whole and then enlarging it, it formed some cracks. I also had trouble closing the box after installing the connections, the tabs for closing it are on the length side, where the connections are. I did manage to close it by cutting some excess plastic from the tabs, but if I decide to buy a new piece, I'll try to avoid the ones with tabs on the length.

In any case, I set it up for a first leakage test and, as expected, it leaked on the cracks that formed. But apparently the connections didn't leak, so that is good. I'll try to seal the cracks, but if I can't, I'll have to buy a new one and think of a better way to drill the holes.

I summarised my build process in an earlier post Horizontal CO2 Reactor - Yugang 鱼缸 Reactor

Here are my tools, and in particular the drill bits I use for the holes. I use plastic, but I was told that there are similar drill bits for glass

 

[Yugang]

Really useful features of AquaRocksColorado prototype are the asymmetric and adjustable water inlet and exit:



I would prefer to have the water inlet always as low as possible, for a smooth and noiseless water flow even at high flow rates and possibly without using a bypass.

The benefit of an adjustable asymmetric water exit is that the reactor power can be adjusted. This is especially useful for overflow mode, or to have optimised inherent safety in the reactor when using a regulator of pH controller.

The power of the reactor is proportional to the surface area, ie the length * width of the water CO2 interface. Half of the reactor filled with CO2 will give the maximum power in overflow mode, as we use the full diameter of the tube, but when rotating the asymmetric water exit the power could be adjusted as per below. The length of the arrow is proportional to the reactor's power in overflow mode, and the ideal design would allow for a (nearly) continuous adaptability between maximum and a very low minimum power setting by rotating the exit end piece.




It would be good if 3 or 4 different reactor sizes were commercially available, for large, medium and smaller tanks. We would select the reactor so that it easily meets or exceeds our pH drop target on our tank and sump (I can support this with calculations and reference table), and then tune down the reactor to get it to push exactly our pH target in overflow mode. For really large tanks, we can combine multiple reactors, as described in the first post.

I believe as a point of reference it could be useful to illustrate what we would need if we wish to tune down a reactor to 50% of its maximum capacity. We then need to position the water exit in its most upright position, and in this position we want the water surface to be 50% of the surface when it is maximum at the full reactor diameter. With a radius r = tube diameter / 2, we want the top of the water exit at 0.86 r above the tube central axis. As an example, when we use a pipe with 100 mm diameter, we want the top of the water exit to be at 0.86*50 = 43 mm above center. When designed like this, the reactor can cover a factor of 2 between minimum and maximum injection in overflow mode.



Note: I edited this post correcting for a calculation mistake

 

[Koan]

This very much makes intuitive sense but thank you for calculating it out!

 

[Yugang]

This very much makes intuitive sense but thank you for calculating it out!

I am helping AquaRocksColorado with fine-tuning the dimensions of their prototype before they take a final decision which reactors to commercialise and produce. To my embarrassment I found a calculation mistake in my previous post, which has now been corrected.

All that I do and calculate in this thread is just the work of one hobbyist, and largely based on measurements in one tank. I am pretty confident it is all good, but as anyone I can make mistakes. One point of uncertainty for example is the 17.7 ratio for a 1.5-1.6 pH drop, but when we build experience with more tanks we may have to adjust this ratio a bit up or down. All I can do is be as transparent and diligent as I can, but I hope that others will check my data and calculations as much and as critical as they can, so that we converge closer and closer to the truth and eliminate any mistakes.

 

[Yugang]

This is my recommendation to AquaRocksColorado, posted with their permission as it would be good to have some feedback from the members of this forum. I am doing all this as service to the community, have no financial/commercial interest, and believe it is also good to have this information transparent on this forum so that anyone can benefit.

First, a detailed drawing of the end of the reactor, with the water exit calculated such that by rotation of the end cap we can tune the reactor down to 50% of its maximum power. AquaRocksColorado are planning all reactors with a 100mm diameter, and the diameter of the water exit at 20mm so that different water hose sizes can be connected with adaptors. I have asked for as much diameter as possible, so as to reduce loss of flow from the pump, even when working with 1 inch tubing as with some canisters.

We see in the diagram how the end piece will be positioned in overflow mode for maximum power, the red line shows that we then use the full 100mm diameter of the reactor. By turning the end piece by a little more than 90 degrees we position the water exit in the top, and the yellow lines show that we use 50% of the tube radius in that case and have 50% reduced power. A flange with many holes around would be useful so that we can make small adjustments between maximum and minimum power.




Then, my advice to AquaRockColorado would be to produce 4 different reactor sizes. My humble opinion is that this reactor should not be exclusively for large tanks, so I calculated that also 45-P and 60-P tanks are not forgotten.

Using the ADA standard sizes as a reference, I calculated the tank surface as well as the estimated (this is my estimation, for a solid guarantee we would need more customer testing) required reactor surface area to push 1.5 pH drop or alternatively 1.2 pH drop.



I tried to configure the reactor sizes so that we have a continuous range from 11.000 mm2 @full power up to 60.000 mm2 @full power, so that we cover all from 60-P (15 gallon) up to 180-P (156 gallon). The smallest reactor can be tuned down to 5.600 mm2, and with that still a viable option for 45-P tanks. Note that this smallest reactor is only 112 mm long, so should be easy to place in a smaller cabinet. Also note that I planned some overlap between reactors, so that users in doubt have a bit of choice between choosing a larger or smaller option depending how hard they want to push on CO2.



Finally, it seems that AquaRocksColorado may also launch a stainless steel version, that not only looks nice but is also timeless. Stay tuned.

 

[Koan]

I am helping AquaRocksColorado with fine-tuning the dimensions of their prototype

Awesome

I'm sure this is completely obvious, but it seems to me the key element of the Yugang horizontal reactor is that, in order to function, it has to be placed and maintained perfectly level at all times.

It is also attached at both ends to a flexible, bendy floppy vinyl hose. One that will get bumped and moved over and over and over again every time a filter or lily pipe is serviced.

Can you make sure that Aqua Rocks Colorado includes a large, easy to see built-in leveling bubble, and several choices of mounting brackets and/ or stabilizing feet, in their design?

It also needs lever-closing quick releases included on both ends, again in order not to interfere with servicing of lily outflow pipes and filter.



Thanks! I feel like these are the kind of smaller details that can get glossed over and missed and ultimately hamper the success of this product.

 

[Yugang]

I hope that this thread is a small contribution to demystifying CO2 for our hobby, and makes CO2 supplemented tanks a bit more accessible for newbies. I am especially hopeful that over time overflow mode will be adopted, and that the reactor will act as set-and-forget as @Unexpected called it.

Unfortunately I still see lots of confusion, and quite frankly even some experienced scapers giving incomplete CO2 advice to newbies. Example in case would be using pH drop method without a proper outgassed reference for pH. Or the importance of surface agitation, which is only partially understood and often statements are not correct from physics perspective.

The dynamic behaviour of CO2 in the tank (pH profiles, ramp up, outgassing, consumption, stability) is not very difficult to calculate for a physicist, it follows quite basic differential equations. But as it is only partially understood by most hobbyists we continue to struggle with it for several decades. Like reactors, we can crack this one when we give it proper attention and as a result new hobbyists can hopefully benefit and feel less challenged by CO2.

I am using my reactor in overflow mode, and it works so well that I am not using a pH probe anymore, and I am good with the most crappy regulator. I have no plan to buy a pH probe, nor a new regulator.

I am not sure if I start experimenting with CO2 again, and recently politely declined when someone asked me to test their prototype commercial reactor. At the same time I feel I owe it to the hobby to help putting the dynamic behaviour of CO2 in a more scientific context, write down the equations or calculations and we could draft a how-to training manual that is consistent with physics.

If any manufacturer feels we need to take this on, is willing to set up some tanks with measurements I am volunteering to do the physics and math so that the hobby can benefit. Alternatively, they may donate a pH probe with data logging, and a CO2 flow meter so that I can do physics measurements (some critical parameters in the equations cannot be found in literature) at home. We can take this one step further than the reactor, clarify dynamic behaviour in the tank and include these in a reliable model and CO2 training manual.

 

[Yugang]

Finally, it seems that AquaRocksColorado may also launch a stainless steel version, that not only looks nice but is also timeless. Stay tuned.

With their permission, I post prototype photos.

 

[Mr.Shenanagins]

Oh I like that!

 

[LMuhlen]

As a follow up for my attempt to build a compact version in overflow mode, I recently bought a few more tools and managed to build it. I tested it with water to look for leaks, and with that out of the way, installed it. Unfortunately, with the water pressure, the lid all but burst open... Hopefully it was so fast that I was still sitting there and managed to control it. Needless to say, water change started earlier that day.

I locked the lid with 4 plastic clamps, but it still wasn't enough. Even if the lid doesn't open, the rubber seal doesn't work under pressure.

I went back to the original configuration for now. I will try a few things to reinforce the lid seal, and I'll test it under pressure, in the garden, before installing it again. But if it doesn't work, I'll just build a normal tubular horizontal reactor.

 

[Yugang]

As a follow up for my attempt to build a compact version in overflow mode, I recently bought a few more tools and managed to build it. I tested it with water to look for leaks, and with that out of the way, installed it. Unfortunately, with the water pressure, the lid all but burst open... Hopefully it was so fast that I was still sitting there and managed to control it. Needless to say, water change started earlier that day.

I locked the lid with 4 plastic clamps, but it still wasn't enough. Even if the lid doesn't open, the rubber seal doesn't work under pressure.

I went back to the original configuration for now. I will try a few things to reinforce the lid seal, and I'll test it under pressure, in the garden, before installing it again. But if it doesn't work, I'll just build a normal tubular horizontal reactor.

Sorry to hear this. I tested above the water line, so no overpressure. Is your box similar to mine?
You may consider to seal with silicon, before closing the lid. I was planning to do that, but never decided to build this small version into my cabinet below the tank.
I hope for some extra goodwill if I don't experiment for a while and keep our appartment tidy, , so am still with my original reactor with the acrylic tube.

 

[LMuhlen]

The way my tank is set, I can't install it above the water line. My box isn't exactly like yours, it is longer and doesn't have the flaps on the large sides, only on the small sides. But that shouldn't be an issue with the recently added plastic clamps (not so sure about the translation here, maybe plastic bands?)

The rubber seal is more "delicate", with sort of an L shaped cross-section. I couldn't find it like yours in plastic, only in glass.

My first plan is to use a lot of silicon grease, since I have it here. If that doesn't work, I'll do the final test with silicon glue, but then I won't be able to iterate on the CO2 functionality, if the insides don't work, it's gone.

 

[Shan_Evolved]

First post. Wanted to thank Yugang and everyone else in this thread for the reactor idea.

I have spent the past few days following this thread and building my own 3"x24" sch 40 PVC reactor based on the 17.7 forumla. This is going to be for a new 125g (72"x18" footprint) style tank I'm currently setting up. I am still awaiting for an inline diffuser to use as an adapter (will take out ceramic ring) before entering the reactor. I will be using a needle valve to hopes to get 1.0-1.2 PH drop. I am worried if I were to do the whole 1.5 PH drop, any fish I put in there would have gassing issues. I have a sunsun 302 only dedicated to co2 (fx6 on the other end) which has 264 gph rated.

Just wondering, how difficult is it going to be to stabilize 1.0-1.2PH drop without a controller and only a precision needle bubble counter valve? I am afraid to go into overflow mode as well. I regret making it so large but want to see how manageable it is.

Attached are pictures. Still waiting on lighting to arrive

 

[Yugang]

First post.

Welcome to ScapeCrunch @Shan_Evolved

3"x24" sch 40 PVC reactor based on the 17.7 forumla. This is going to be for a new 125g (72"x18" footprint) style tank I'm currently setting up.

Checked this, correct.

I am worried if I were to do the whole 1.5 PH drop, any fish I put in there would have gassing issues.

Remember that this 1.5 pH drop is from fully outgassed. Just saying, as I see a lot of confusion, for example in FB, where pH drop is incorrectly referenced to the morning pH in the tank when CO2 goes on. I may be wrong, but believe that in a planted tank with good oxygen levels a 1.5 pH drop from fully outgassed will rarely, if ever, give problems for the fish.

I regret making it so large but want to see how manageable it is.

You can always use your precision regulator to set your injection, and the reactor will work just as any other reactor. The benefit is that thanks to its design you have capped your maximum pH drop to 1.5, even if anything goes wrong with injection.

Just a note on your bypass - it is helpful if bubbles escaping from the reactor follow a tube that goes upwards toward the tank, not down.

If there is any help I can give @Shan_Evolved send me a PM.

 

[Shan_Evolved]

Just connected it.

Thank you for your wisdom YG!

I have to say I am baffled at how quiet it is. I even have my bypass fully open and I'm getting a gentle stream. This is amazing! Let's see how the co2 reacts. I will use a drop checker as well as track my PH

 

[Yugang]

I even have my bypass fully open and I'm getting a gentle stream.

I see that your reactor is above your bypass, so the water exit tube from the reactor goes down, not up. This can work, but you need enough flow in your reactor so that bubbles will be taken with the flow, and go down. If the water flow is too slow, it may happen that the reactor and tubing above the bypass will fully fill with CO2 and the reactor function will be lost.

it is helpful if bubbles escaping from the reactor follow a tube that goes upwards toward the tank, not down.

All what I am saying here only applies for overflow mode. When using the reactor below its max capacity, regulator or pH controller, there is no concern.

 

[Shan_Evolved]

I see. I had the bypass open and closed but the level of water in my reactor remained the same (70%). I closed the bypass and will see if any changes to co2. I have so far reached green drop checker within an hour. It took me over 3 hours previously