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.