# Upside Down Bottle Diffuser



## Antonius Setiadi Khengdro (Jul 13, 2018)

Hello! I'm still new to this forum. But I like to read from afar whenever I found problem in my tank and it has been really helpful ! 

So recently I wanted to try CO2 for my planted shrimp tank. My tank are fully cycled. 
(I never use CO2 because I read that it's sometimes could kill my shrimp).


Then I found this video. 






At the first couple minutes. The owner of the aquarium using an upside down bottle to diffuse his CO2. 
This is my first time seeing it. 
He had some Styrofoam inside (I wonder what this is for) and how he stick it to the aquarium? 

Will this method be safer for shrimp and fish?
Do any of you guys are using this DIY tools and have any experience with it?
Because I wanted to try it for my soon planted tank for fish and my current shrimp.
Both of my tank are 10 Gallon.


Thanks. :laugh2:


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## MCFC (Feb 12, 2017)

Buddy has to refill his bottles every couple days. Go with pressurized CO2 on two 10 gals and you'll probably have to refill the bottle every 6 months haha.


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## tamsin (Jan 12, 2011)

The syyrofoam is just to make the CO2 level more obvious, it sits on the water surface so moves up in the bottle as the CO2 is depleated. When it hits the top you need to refill.


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## zerodameaon (Dec 2, 2014)

Unless you have like 100 10 gallon tanks just get a pressurized system that can run both tanks, or two individual pressurized systems.


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## DigityDog70 (Jan 20, 2017)

This is the best approach to Co2 not to mention a bang for the buck. If you have more than one tank I like this. Even a show tank you could just hide the Co2 in the sump. I just started doing this. I'm using a rock to keep the bottle weighed down. It's so efficient it's almost comical. My plants are thriving.


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## Blue Ridge Reef (Feb 10, 2008)

I've been doing it this way for several years and full disclosure it's wearing on me. You won't get those sweet 30 PPM readings, but can reach about half of that which makes a huge difference. Mine have to be filled daily with 32 oz bottles on 50 gallon aquariums. They are probably out of CO2 within 6 hours. When I do my next big tear down, I'll probably go back to pressurized TBH. This method does work, but it's one more thing to have to do every day. Pressurized can be set lower to ensure safe levels for your livestock easily enough.


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## Desert Pupfish (May 6, 2019)

Blue Ridge Reef said:


> I've been doing it this way for several years and full disclosure it's wearing on me. You won't get those sweet 30 PPM readings, but can reach about half of that which makes a huge difference. Mine have to be filled daily with 32 oz bottles on 50 gallon aquariums. They are probably out of CO2 within 6 hours. When I do my next big tear down, I'll probably go back to pressurized TBH. This method does work, but it's one more thing to have to do every day. Pressurized can be set lower to ensure safe levels for your livestock easily enough.


Nice to hear that this works for you, but sounds like a hassle. Are you doing DIY CO2?



DigityDog70 said:


> This is the best approach to Co2 not to mention a bang for the buck. If you have more than one tank I like this. Even a show tank you could just hide the Co2 in the sump. I just started doing this. I'm using a rock to keep the bottle weighed down. It's so efficient it's almost comical. My plants are thriving.


Curious to know how many bottles in what sized tank? And how often do you need to refill them? From what Blue Ridge Reef posts below it sounds like it can be a hassle for larger tanks/

Thanks!


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## DaveKS (Apr 2, 2019)

Desert Pupfish said:


> Nice to hear that this works for you, but sounds like a hassle. Are you doing DIY CO2?
> 
> 
> 
> ...


These type things are better run on low yield yeast generator, doesn’t need high pressure, just has to be able to push co2 underwater and output a bubble about every 4-5sec to keep bell filled up. It actually produces more than co2 bell needs so every once in a while it will just burp out excess, it’s free co2 so no problem. I’d go 2months on single charge of yeast reactor. Lots of sugar, very little yeast and couple chunks shell/coral as buffer.


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## Blue Ridge Reef (Feb 10, 2008)

Desert Pupfish said:


> Nice to hear that this works for you, but sounds like a hassle. Are you doing DIY CO2?


I fill from a pressurized tank every morning. No DIY for me, I know some people have luck that way but I never cared for it.


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## Desert Pupfish (May 6, 2019)

DaveKS said:


> These type things are better run on low yield yeast generator, doesn’t need high pressure, just has to be able to push co2 underwater and output a bubble about every 4-5sec to keep bell filled up. It actually produces more than co2 bell needs so every once in a while it will just burp out excess, it’s free co2 so no problem. I’d go 2months on single charge of yeast reactor. Lots of sugar, very little yeast and couple chunks shell/coral as buffer.


Thanks, @DaveKS. So could you use one generator and split the output between two bottles/bells then? Like Blue Ridge, I've got a 55g that would likely require two bells, so thinking splitting the output between them would keep from losing any CO2 (even if it is "free"--though I count my time & effort as an expense)


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## Edward (Apr 11, 2005)

CO2 generator recipe

1 L tap water KH > 5 degrees
200 grams sugar
1 gram or 1 / 5 tsp Miracle-Gro 24 – 8 – 16
10 ml or 2 tsp pure tomato paste
1 / 5 tsp Fleischmann’s Traditional baking yeast

1.077 original gravity 
10% ABV ethanol
21 °C or 70 °F ideal temperature
1 month fermenting

Passive reactor results
Passive reactor designs


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## DaveKS (Apr 2, 2019)

Desert Pupfish said:


> Thanks, @DaveKS. So could you use one generator and split the output between two bottles/bells then? Like Blue Ridge, I've got a 55g that would likely require two bells, so thinking splitting the output between them would keep from losing any CO2 (even if it is "free"--though I count my time & effort as an expense)


No you just use 1 bell, it’s very hard to balance out distribution on multibell system. If one output is just a hair higher in water then gas will go to that one. Instead of 2 bell think one longer flatter bell. The square in of bubble size in contact with water column is what you use to control it, not going to multiple bells. In a yeast driven system that’s constantly being filled you don’t really need a big tall vessel, all that gas area above the water/gas contact interface in a big tall bottle is doing nothing, it’s just a reservoir for gas, co2 exchange happens only at actual water/gas interface at bottom.

Think long and flat, like a drawer organizer turned upside down vs a tall vert bottle. A big long bubble that’s 10x2 will give you 20sq in of gas/water contact area, a vertical bottle may only have a 3x3 gas/water contact area, 9sq in. Think you can figure out which one will give you the higher co2 dissolution rate into water. It barely has to be in water, just far enough to trap gas under it.










In your tank a 8x2 bubble will do a nice job. You can even use stainless steel mesh to make a bell, it not only has 100% gas to water contact area on bottom of bubble but also has around 40% contact area on top through mesh so you can make it even smaller. Doesn’t need a reservoir above it because it’s constantly being replenished by yeast canister, all it has to do is hold a thin bubble of a certain sq/in underwater.


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## DigityDog70 (Jan 20, 2017)

I use PVC, tie the bottle inside to the PVC and drape the PVC out the back on some tanks and over the front on other tanks, using a Platic Zip tie, works great. It's work but I only have to refill my small Gatorade bottles every 2-3 days. It depends how you place the bottles in the tank, how many plants you have and how large a tank is. I recommend this approach as you will learn from it and it has its pros and cons, but caring for your tanks is part of the hobby I enjoy. My plants definitely like it.


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## DigityDog70 (Jan 20, 2017)

The bottles that are securely fastened with a zip-tie, diffuse CO2 at a slower rate vs the bottles that are suspended just under the tank lid. It seems like the CO2 in the bottle, that causes the bottle to rise up, also causes the CO2 to be forced out more rapidly. I know that may not make sense, it took me a few days to figure it out, but I'm pretty sure this is an accurate assessment.


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