Help Yugang CO2 Reactor fittings MOD and my pH drop Problem

[BigWave]

After reading all the information, discussions and math on the new Yugang CO2 Reactor I thought I would give it a try setting up this new tank. I ordered a small clear Yugang CO2 Reactor from Aqua Rocks Colorado. Had to do some slight modifications to get it to fit inside the stand. AKA removing the 45 degree fittings and installing 90 degree ones in their place. The fittings modifications worked crudly but effective. Due to the manufacturer using metric 25mm fittings and myself being in the USA I had to settle for 3/4" inch ones. This made it leak so to remidy this I had to make gaskets out of aquarium silicone. These were placed between the OG Union fitting and my new 3/4" union fitting.

 

[BigWave]

Here is a pic of the tank and planting. It is a UNS60U. 60 cm long x 36 cm wide.



Dont mind the curvature of the image That is from my 32" curved monitor.

 

[BigWave]

Pictures of the Reactor and fittings modifications...

3/4" 90 degree fittings slip fit
3/4" to 1/2" reducer bushings slip fit
1/2" barb to slip fit inserts
3/4" unions - Note: Ideally 1 inch would have worked better but then I would have had to sand down the outside diameter of the union inserts. The problem is the new union inserts hole is bigger then the OG 25mm union hole thus creating a gap. This gap I had to fill by creating silicone gaskets. Yes, yes I should have ordered the correct 25mm ones but geezzzz their expensive and shipped from overseas.



Chopped the 90's and reducing bushings down for minimal size.



Everything dry fit. Always dry fit before gluing!!!



New fittings vs old OG fittings.



Installed on the reactor.






Unfortunately I did not get any pictures of the gasket I made due to silicone everywhere and water all over the cement floor from it leaking.

 

[BigWave]

Here is the hole sizing issue I just took pics of with left over peices.



Also you will notice the threads are just a little different but it did snug down tightly.

 

[BigWave]

OK the reason for this post. My pH drop problem. I have done the math over and over. This reactor should support my tank 2 to 3 times over, but it does not. I have tried having the CO2 enter from the top and from the bottom via the provided fitting on the reactor. I have rotated the output hole from the top down to the bottom and all other angles. I have adjusted my regulator pressure up and down. Even the needle valve up and down. Set the CO2 output as per @Yugang recommendation of it burping every minute or so. It gets the water down below the lip of the output hole (at the bottom) with a constant burp / release of CO2.

Before some pics tank stats:
Tank: UNS60U
Substrate: 1x 9 liter bag Tropica soil, 1x bag worm castings.
Light: NA Prizm 16"
Filters: 2x Eheim 2211 canisters with 2213 impeller upgrades. (I do have the 2213s i could swap out if need be)
CO2: 5lb bottle with Alan Le regulator
pH at tap: 7.2
Tank pH degaused for days: +-6.0
Tank pH after 8 hrs of CO2 +-5.5 it will never get any lower no matter what I do.
gH: 2-4 (dosing 20ppm Ca, 8ppm Mg at water change)
kH: 0
TDS : Out of tap 23

pH check using Imagitarium multi range test kit




Regulator pressures


Measurement of water line with out CO2 on the top vs with CO2 on the bottom.


Bubble counter going crazy
View attachment VID_20251121_074542.mp4

The only thing I could possibly come up with is my canister isnt powerful enough and the reactor needs more flow going through it. Any thought???

 

[hamfist]

Flow should really not be a problem. The more usual problem is too much flow causing excess noise and unstable water level within the reactor. My experience and other's reports is that a really low flow should not effect efficiency at all. I find using around a 400-500 lph flow through my reactor into a 450 litre tank works great. For your tank I would think an Eheim 2211 output flow should be ample. Book value is 300 lph, so in reality you should be getting at least 200 lph I would think. Should be fine.

What is the actual gas/water interface surface area within your reactor when its running ? Visually it looks like it should be ample for the tank surface area but its worth discussing nonetheless. My reactor has a 236cm2 gas interface area, but this is on a 450 litres water volume tank (9000cm2 surface area). THis still achieves a 30 ppm CO2 level despite 2 x spray bars pointing at the surface for ample surface disturbance. CO2 levels measured directly using a Hanna test kit.

Its a little odd your tapwater pH being so much higher than your degassed tank sample. Due to all the assumptions one has to make using the pH drop method to "guess" CO2 levels I am a strong believer in measuring CO2 levels more directly to actually know whats going on. The Hanna liquid drop test is reasonably cheap and is definately step nearer knowing actual CO2 levels in one's tank . Its quite possible that your reactor is actually amply efficent once real CO2 levels are measured.

 

[BigWave]

I was just reading the thread about that test kit and ordered one. Should be here in a few days.
My only concern is the amount of CO2 being lost (burped) out. Been in the hobby many years and know or see my bottle will be out in weeks. Filling up here past Seattle gets expensive quick.

 

[BigWave]

Hmm,
Yugang CO2 Reactor Small
10cm x 36cm
Surface are: 10x36 = 360cm2

UNS60U
60cm x 36cm
Surface area: 60x36 = 2160cm2
2160 / 17 = 127.058

 

[Naturescapes_Rocco]

I'll chime in once I get home!

 

[Mr.Shenanagins]

Chosen oneI'll chime in once I get home!

Pretty sure this is actual raw footage of @Naturescapes_Rocco contributing to this forum.

 

[Naturescapes_Rocco]

Pretty sure this is actual raw footage of @Naturescapes_Rocco contributing to this forum.

As long as it's not too much or people don't get annoyed that I answer a lot, I'll keep going!

 

[Naturescapes_Rocco]

@BigWave I actually don't have anything to add other than to wait and try the Hanna test kit. I find liquid pH test kits to be really difficult to use, but I've also found pH drop testing to be inaccurate compared to the Hanna test kit! It's been a game-changer. Let us know what your results are the with Hanna kit!

On second thought: do you have a drop checker you can also compare to? That would be really useful to compare with!

 

[techman81]

I'm no expert but I'll chime in with my limited but recent experience. Like Rocco, I've found "PH drop" to be an inaccurate way to measure CO2, and I would say, it's even less accurate than a drop checker. I've never seen a 1.0 PH drop in my year old 49 gallon tank and yet I know by a drop checker and the Hanna test kit, my CO2 levels are over 45ppm. I'm currently cycling a tank similar in size to yours and testing my DIY reactor. I have it calibrated for about a 1.2 ph drop per Yugang calculations and yet I've only seen, like you, a .5 to .6 ph drop (6.3 to 5.7). My drop checker however tells a much different story and I suspect CO2 is even higher than I want it (haven't tested with the hanna test kit yet).

I have one of the small reactors from ARC that I haven't used yet but I know, even at the lowest setting, if CO2 is burping every minute on the size tank you have, you'd probably be gassing your fish. I think that reactor can only be used on a tank that size in regulator mode (if I'm understanding regulator mode correctly). My DIY reactor (I'm redesigning since my first was too small diameter) will be similar diameter to the ARC reactor but less than half the length.

 

[BigWave]

Thanks @Naturescapes_Rocco and @techman81 I will keep everyone posted. Dont have any drop checker liquid left but know how to make it easily.

From Google Gemini:
To make a 4 dKH solution using NaHCO₃ (sodium bicarbonate) in 1000 mL (1 liter) of H₂O (distilled or RO water), you need 0.12 grams of NaHCO₃.
Method:

1. Measure Water: Accurately measure 1000 mL of pure distilled or reverse osmosis (RO) water. Using tap water or spring water will result in an inaccurate concentration due to existing minerals.
2. Weigh NaHCO₃: Accurately weigh 0.12 grams (or 120 milligrams) of fresh sodium bicarbonate. A precision scale is required for this small amount.
3. Mix: Add the measured NaHCO₃ to the 1000 mL of water and mix thoroughly until completely dissolved.

This will yield approximately 1 liter of 4 dKH solution.

Then simply add bromothymol blue (common pH indicator) to whatever desired color intensity desired.

 

[tjcline0]

I had the exact same experience with my DIY build (not the aqua rocks version). I followed the original formula for my tank UNS 120U and used 3" x 21" PVC. I could only achieve 15ppm CO2. This past weekend I built a new one. I exactly doubled the reactor area from the original and am getting bang on 30ppm of CO2. I used lab grade equipment to measure. This reactor is a monster (4" PVC x 35"). Not sure what's up with my original build. But I'm happy now. I have exactly the CO2 I want, day after day, with no risk of gassing my shrimp colony.

 

[BigWave]

Im not a fan of this reactor design, that is for sure. I will not recommend it to anyone.
It took well over a month to receive my Hanna CO2 Test Kit. 2 different vendors cancled their order due to lack of stock so got it directly from the manufacturer for a steep shipping price. The entire time I struggled. Always to much or not enough CO2. I have now dialed in the CO2 level to about 40ppm via the test kit and observation of drop checker and indicator plants response:: Tulu, Meta, Syngs and Wallichii). I still dont trust it. All my years in the hobby tinkering with cheap metering valves, $300 dollar ones, custom regulators I have always had steady consistent CO2 levels where you can not see the bubble counter going its so fast. With this reactor the bubble is about 1 a second, like painfully slow. As they say trust your gut which is especially true in this hobby. If it seems off, looks different, plants arnt the same color, sheen etc its a good indicator something is off.
My biggest complaint and WARNING for any one else, is the constant transfer of water from the reactor to the tank and vis versa daily. I have this reactor on a UNS60U 20 gallon tank with 2x viv lily pipe sets. The natural water level sits just high enough so it doesnt make noise all the time about 1.5 inches down the side of the tank. When the CO2 turns on and fills the reactor thus pushing water out into the tank its about 5/8th's from the rim. If I remove some water then the waterline falls below the lily pipes when CO2 turns off. Its a daily thing to add or remove water. Biggest pain in the ass ever. My sump on the 93 gallon doesnt even do this!!
I would have purchased all the parts to make my own but alas it would have cost more than to just buy the store bought version.

Anyways, tank and plants are looking more healthy now. There is growth unlike before but still fighting new tank syndrome and the constant Green Dust Algae outbreaks.

 

[Koan]

the constant transfer of water from the reactor to the tank and vis versa daily. I have this reactor on a UNS60U 20 gallon tank with 2x viv lily pipe sets. The natural water level sits just high enough so it doesnt make noise all the time about 1.5 inches down the side of the tank

That's interesting challenge for a small tank

@Naturescapes_Rocco you use a ton of these, any of them on little tanks?

I know @*Ci* has used the spraybar version of this reactor effectively on small tanks, that would bypass this problem altogether. It's a trick to make pretty but she has pulled it off

 

[techman81]

That's interesting challenge for a small tank

@Naturescapes_Rocco you use a ton of these, any of them on little tanks?

I know @*Ci* has used the spraybar version of this reactor effectively on small tanks, that would bypass this problem altogether. It's a trick to make pretty but she pulled it off

I'm definitely not an expert on these, but as I mentioned previously in this thread, the ARC small reactor, even on the lowest setting is really too much for a 20 gallon tank. Having said that, I'm really confused as to why the water level would be changing with CO2 coming on and turning off. Water should be running through the reactor the same way all the time. I have a smaller DIY reactor on my 25 gallon tank that is running just fine with normal lily pipes.

 

[Naturescapes_Rocco]

Having said that, I'm really confused as to why the water level would be changing with CO2 coming on and turning off. Water should be running through the reactor the same way all the time. I have a smaller DIY reactor on my 25 gallon tank that is running just fine with normal lily pipes.

Actually, @BigWave is correct. The water level fluctuates in these reactors.

When CO2 is off, especially when it's been off all night and is about to come on, the gas pocket will be at the smallest.
When CO2 is injected, especially when it's been on all day and is about to turn off, the gas pocket will be at it's largest.

The displacement of that water has to go somewhere. In my large tanks, it makes the water level fluctuate a few mm throughout the day.

If I do a water change and purge the reactor of all gasses while the water is refilling, then run the tank, by 3pm the next day the water level in the tank will have actually risen because the displacement from the reactors. All the water that was in that reactor has to go somewhere when it gets replaced by CO2/atmospheric gas via injection!

Over time, there is a more steady equilibrium reached, where the gasses within the tank and reactor begin stabilizing to some degree, but I haven't owned or used a reactor that doesn't fluctuate some amount of gasses throughout the day.

@Naturescapes_Rocco you use a ton of these, any of them on little tanks?

The smallest tank I've tried is my 39gal Experiment Tank. The reactor is a bit oversized, so if I push it to 45ppm CO2 injection the water displacement definitely pushes the level of the tank upwards, but it's never been an issue for me.

I also use auto-top offs in both of my tanks, and have for over a year now. They aren't majorly affected by the changing water levels, either. It's hard to picture Bigwave's reactor being big enough to cause that much displacement each day, but maybe in a small tank or a tank with a specific volume. For example, the 60U is a fairly "tall" tank, so it would experience more daily water level fluctuation than my more "horizontal" tanks.

They still work great for me, but I understand that not everyone's setup will work! Everything in this hobby is about pros and cons, there's no one single best setup (though I wish there was).

 

[techman81]

The displacement of that water has to go somewhere. In my large tanks, it makes the water level fluctuate a few mm throughout the day

OK, after re-reading the post, I get what @BigWave was saying now and yes, I understand that the water level does have to fluctuate to some degree, but as in the case with your tank, it's only a few mm on mine. So I guess if your lily sits very close to the surface (mine is about a 1/4") it could be an annoying issue. In the case of my 25g, those few mm of fluctuation don't pose a problem. But in bigwave's case, he's describing a fluction of 7/8". Unless I'm just not thinking clearly, that would mean a very large gas pocket in the reactor which would result in very high co2 levels in the 20g tank.