# How To: DIY co2. Secret Formula



## Marc Davis

Hi guys, I'm sure you all know how to make co2, but i made this video to help newcomers to planted tanks. With such an easy way to make co2 and the massive impact it has on your plants, it should be a must for most planted tanks (that have any decent depth to them).

I know i found this forum when i was looking for diy co2 methods and found i needed something a bit more instructional so i made this video:

I hope the video answers any questions but if it doesnt then ask away:


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## zozo

We have a television program called (Literaly translated) Value Inspection Service.. It's kinda my favorite.. They have formed a team and scavange supermarkets select products and bring it to laboratories for investigation etc. etc. Lots of things are revealed and some are actualy quite shoking sometimes and makes you think why the hell am i buying that stuff. Anyway, not that long ago Sugar was under investigation, the question was "What is the differnce between Brown and White sugar?" Same procedure, laboratories and independed professionals were interviewed.

Conclusion was!?.. The difference next to the color is 0 and it's purely aesthetics and peace of mind if you feel like brown is beter or different and don't mind to spend an exra dime on iit. You are good to go.. But there is no chemical difference in brown and white sugar both are 100% identical.


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## Marc Davis

zozo said:


> We have a television program called (Literaly translated) Value Inspection Service.. It's kinda my favorite.. They have formed a team and scavange supermarkets select products and bring it to laboratories for investigation etc. etc. Lots of things are revealed and some are actualy quite shoking sometimes and makes you think why the hell am i buying that stuff. Anyway, not that long ago Sugar was under investigation, the question was "What is the differnce between Brown and White sugar?" Same procedure, laboratories and independed professionals were interviewed.
> 
> Conclusion was!?.. The difference next to the color is 0 and it's purely aesthetics and peace of mind if you feel like brown is beter or different and don't mind to spend an exra dime on iit. You are good to go.. But there is no chemical difference in brown and white sugar both are 100% identical.



I heard this too. But i've done the exact same batches with and without the brown sugar and found that the brown sugar one lasted nearly a week longer @ minimum 1 bubble per second. Apparently its down to the molasses in brown sugar??


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## zozo

Marc Davis said:


> I heard this too. But i've done the exact same batches with and without the brown sugar and found that the brown sugar one lasted nearly a week longer @ minimum 1 bubble per second. Apparently its down to the molasses in brown sugar??



No idea, the investigation got triggered by an urban myth that sugar producers artifialy colored sugar brown to get more money out of it. For that no evidence was found... But the laboratory report stated. It doesn't make a difference anyway. Conclusion was both are 100% identical from a molucelair sugar perspective. White sugar is made from beets and brown from cane, but in the end sugar is sugar.. That's all i know.

Are you sure it's from the sugar?.. Temperatur also plays a major role in the yeast activity..


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## dw1305

Hi all,





Marc Davis said:


> I heard this too. But i've done the exact same batches with and without the brown sugar and found that the brown sugar one lasted nearly a week longer @ minimum 1 bubble per second. Apparently its down to the molasses in brown sugar??


You get a longer, more controlled reaction, if you use gelatin to reduce sugar availability. Search for the "DIY CO2 Jello method".

cheers Darrel


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## Marc Davis

dw1305 said:


> Hi all,You get a longer, more controlled reaction, if you use gelatin to reduce sugar availability. Search for the "DIY CO2 Jello method".
> 
> cheers Darrel


How long are we talking? I get two weeks out of the above method. You think its possible to get even longer? (with minimum 1 bubble per second).


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## dw1305

Hi all, 





Marc Davis said:


> You think its possible to get even longer?


It should be. 

Try adding some sodium bicarbonate (NaHCO3), it will slow acidification of the solution, another possibility is to use a "champagne yeast", it will tolerate higher levels of alcohol and acidity than baker's yeast (you don't need the baking powder with wine yeast).  

Other options are adding some of a less accessible carbohydrate source (corn flour) as well as the sugar.  I thing there might be advantages to the <"Jello-method"> in terms of how easy a new culture is to set-up.

cheers Darrel


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## Marc Davis

dw1305 said:


> Hi all, It should be.
> 
> Try adding some sodium bicarbonate (NaHCO3), it will slow acidification of the solution, another possibility is to use a "champagne yeast", it will tolerate higher levels of alcohol and acidity than baker's yeast (you don't need the baking powder with wine yeast).
> 
> Other options are adding some of a less accessible carbohydrate source (corn flour) as well as the sugar.  I thing there might be advantages to the <"Jello-method"> in terms of how easy a new culture is to set-up.
> 
> cheers Darrel



Well there is definitely some more experimenting to be had!


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## BubblingUnder

zozo said:


> Are you sure it's from the sugar?.. Temperatur also plays a major role in the yeast activity


From my Home Wine making days I remember that you can buy heater mats for the bottle to control the reaction. Higher temperature for faster reaction & higher CO2 production for a shorter period. Very tasty.


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## AverageWhiteBloke

Also coming back to my wine making days, you can buy sherry yeast which tolerates higher alcohol volumes. The problem is with maintaining a steady ferment rate. The process goes through three stages, aerobic which is quite slow, anaerobic which is vigorous and the tail end which is slow as the yeast dies off through high acidity and alcohol content. I found back in the day I had better success using two bottles spread a week or so apart. Also once you have the first two bottles going don't start a fresh one and skip the aerobic part, you're better off just leaving some yeast sediment in the bottle from the previous ferment which is already good to go in an anaerobic state and putting the the new sugary liquor over the top of that which gets going quicker. I found skipping aerobic and tail end yielded best results and try to keep two bottles at some stage of the anaerobic process. Gas works out better in the long run but good for a meddle. Coming back to the difference, I know in some wine making books some recipes favour brown sugar to white for certain wines like rice for instance so their must be some difference in the final taste if nothing else.

I watched a quite interesting programme about sugar quite a while back, apparently if sugar had just been invented today they would probably ban it on health grounds! It was the cocaine of the day, up until sugar came around people got their sugars just from indigenous fruit and veg in small quantities so when they had something with sugar in it was like a massive high. Only the very elite had access to it in small amounts and apparently a good land owner would now and again allow their workers a cup of tea or something with sugar in as a treat. Supposedly this came more and more common place and this is where the 10am brew came from which is now enshrined in most work places. In UK culture not having a brew would now be frowned upon.

Just putting that out there


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## AverageWhiteBloke

Just to add, keeping two bottles mid anaerobic means the second bottle quickly pushes out the air from the other bottle after you've opened it so tends to get going with the old yeast pretty much straight away rather than waiting 24 hours. You can buy a ready made kit off ebay which takes two bottles for under £20 to save messing about and making your own.


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## AverageWhiteBloke

Just been thinking back there. I remember something about an over vigorous ferment causing a bad taste trait to certain wines - can't remember what that was now. However the solution was to have a slower, steadier ferment and the way to get round this was to mix up the sugar liquor so that it was destined to be no higher than 10% alcohol using SG gravity thing as a guide when the sugar had completely fermented out. You add this solution in 100ml increments over a period of time. I wonder if that might work and maybe add the new batch at night effectively switching the co2 turning the co2 down over the dark period and it would get up to speed by the next day.

I'll dig the book out and see what the sugar to water ratio was again. 

Sent from my STH100-2 using Tapatalk


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## BubblingUnder

AverageWhiteBloke said:


> maybe add the new batch at night effectively switching the co2 turning the co2 down over the dark period and it would get up to speed by the next day


You could also put a heater mat on a timer, extending the overall fermentation period & reducing CO2 production overnight but increasing during the day when the mat warms up, though it might take a bit of trial & error to get right.


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## AverageWhiteBloke

BubblingUnder said:


> You could also put a heater mat on a timer, extending the overall fermentation period & reducing CO2 production overnight but increasing during the day when the mat warms up, though it might take a bit of trial & error to get right.


Therein lies the problem mate, unless you already have the equipment to hand you start getting into the territory of a gauge and bottle. I wouldn't try and use DIY on anything over say 50 ltrs. You could probably pick up a gauge with needle valve for Under £50 and a fire extinguisher which would last quite a long time on a tank that size. After that it's just refilling the FE but you have far more control over what's going on in the tank unlike DIY which has its limits. Co2 is like a drug to plants I find and if there's lots of fluctuations you get lots of problems. 

Having said that, as long as the lighting isn't over the top and the plants aren't too demanding trickling in a bit of co2 through DIY can improve the overall health in the tank.

I couldn't find my book just now but I'm pretty sure about 3 pound of sugar in a gallon of water yields about 14% volume of alcohol when fully fermented. Getting that last 4% would be a slow process as the yeast was dieing off and the wine is effectively sterilising itself. If I was to have a pop again on a low lit tank just for a bit of a boost I think I would make up 2 pounds of sugar to a Gallon of water but keep in a separate container. Start off maybe a 2 ltr bottle with 500ml in then once it got going keep adding a 100ml or so of the original mix every couple of days at night until the bottle was full and repeat. I would say that would give you the longest steadiest ferment rather than it trying to burn off all the sugar in one go then tail off. 

Every time you add some more of the mix you would be diluting down the acidity and alcohol content as well. Sort of drip feeding it if you like would be my guess.

Sent from my STH100-2 using Tapatalk


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## Marc Davis

AverageWhiteBloke said:


> Therein lies the problem mate, unless you already have the equipment to hand you start getting into the territory of a gauge and bottle. I wouldn't try and use DIY on anything over say 50 ltrs. You could probably pick up a gauge with needle valve for Under £50 and a fire extinguisher which would last quite a long time on a tank that size. After that it's just refilling the FE but you have far more control over what's going on in the tank unlike DIY which has its limits. Co2 is like a drug to plants I find and if there's lots of fluctuations you get lots of problems.
> 
> Having said that, as long as the lighting isn't over the top and the plants aren't too demanding trickling in a bit of co2 through DIY can improve the overall health in the tank.
> 
> I couldn't find my book just now but I'm pretty sure about 3 pound of sugar in a gallon of water yields about 14% volume of alcohol when fully fermented. Getting that last 4% would be a slow process as the yeast was dieing off and the wine is effectively sterilising itself. If I was to have a pop again on a low lit tank just for a bit of a boost I think I would make up 2 pounds of sugar to a Gallon of water but keep in a separate container. Start off maybe a 2 ltr bottle with 500ml in then once it got going keep adding a 100ml or so of the original mix every couple of days at night until the bottle was full and repeat. I would say that would give you the longest steadiest ferment rather than it trying to burn off all the sugar in one go then tail off.
> 
> Every time you add some more of the mix you would be diluting down the acidity and alcohol content as well. Sort of drip feeding it if you like would be my guess.
> 
> Sent from my STH100-2 using Tapatalk


My tank is 200L and I have my lights (2x T8 and 30w LED floodlight) on for 16 hours a day and i can assure you that my DIY co2 costs bugger all and does far more than improve the overall health in the tank.


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## AverageWhiteBloke

Marc Davis said:


> My tank is 200L and I have my lights (2x T8 and 30w LED floodlight) on for 16 hours a day and i can assure you that my DIY co2 costs bugger all and does far more than improve the overall health in the tank.


I've no doubt it does mate. Any additional source of co2 dissolved into the water will improve the growth without a doubt. I was more meaning if you start buying equipment to keep co2 stable like heaters or the stuff I posted. Co2 equipment is very cheap these days as is gas. I pay £15 pound for 5kg, not sure how many bags of sugar I would have to buy to generate 5KG of co2 but there will be a monetary value. 5KG lasts me about a year in 100ltr tank keeping a lime green drop checker when I need it. Say I spent 5 or 6 quid maybe even more on bags of sugar over the year to keep a diy setup going you can see the difference is starting to get negligible. I'm paying a few quid a year to have total control over the co2 levels. 

You can actually work out how much diy co2 production costs if molar weights and maths is your thing to see what a bag of sugar would generate but that would just be a bit pointless. Someone in here will do it though I bet  https://lifefermented.wordpress.com/2014/01/22/how-much-co2-is-produced-from-brewing/

Your tank is in good shape. Been watching it on YouTube. Not sure what you mean by "Far more than improve the overall health" though. It's definitely benefiting from the extra co2. Diy has a niche I find. When people are running really high end lighting they often run into co2 related issues even with a lot of control over its Injection using quite expensive regulators and needle valves. Imagine trying to do this when the only thing you can do is sit, watch and see what happens. 

Sent from my STH100-2 using Tapatalk


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## Marc Davis

AverageWhiteBloke said:


> I've no doubt it does mate. Any additional source of co2 dissolved into the water will improve the growth without a doubt. I was more meaning if you start buying equipment to keep co2 stable like heaters or the stuff I posted. Co2 equipment is very cheap these days as is gas. I pay £15 pound for 5kg, not sure how many bags of sugar I would have to buy to generate 5KG of co2 but there will be a monetary value. 5KG lasts me about a year in 100ltr tank keeping a lime green drop checker when I need it. Say I spent 5 or 6 quid maybe even more on bags of sugar over the year to keep a diy setup going you can see the difference is starting to get negligible. I'm paying a few quid a year to have total control over the co2 levels.
> 
> You can actually work out how much diy co2 production costs if molar weights and maths is your thing to see what a bag of sugar would generate but that would just be a bit pointless. Someone in here will do it though I bet  https://lifefermented.wordpress.com/2014/01/22/how-much-co2-is-produced-from-brewing/
> 
> Your tank is in good shape. Been watching it on YouTube. Not sure what you mean by "Far more than improve the overall health" though. It's definitely benefiting from the extra co2. Diy has a niche I find. When people are running really high end lighting they often run into co2 related issues even with a lot of control over its Injection using quite expensive regulators and needle valves. Imagine trying to do this when the only thing you can do is sit, watch and see what happens.
> 
> Sent from my STH100-2 using Tapatalk



True true. When I say far more than improve health, I meant more than just a little bit.

The difference between no co2 and even 1bps seems to be HUGE in my limited experience.

I used to be struggling with algea, poor growth to no grown. Plants melting. Whole tank being dull looking. Then I thought I'd try the diy method because the wife wouldn't allow the cost of regulator and tank and what not. I couldn't believe the difference in just a few days. I feel bad for anyone who doesn't run some form of co2  now. That's the main reason I made the video. Tiny bit of effort and all your dreams of lush green plants filling everywhere as you had imagined just happen.


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## AverageWhiteBloke

Definitely pal. Good maintenance and flow like your tank has goes a long way and sometimes with moderate enough lighting you can get away without co2 even with plants that are supposed to like co2. Even with everything on point a tank can be just on the edge and that little drop of co2 is just what the plants were waiting for to flourish.

I have a similar setup that was low lit and ran with no co2 for some time. Everything was just OK, plants were healthy but they just lacked that something. I'm fortunate enough to have a couple of regs kicking around that I've picked up second hand over the years on the cheap and access to cheap FE 'S or pub bottles refills so running the tank without was choice to see what I could get away with. I bottled it and put a diffuser in the tank, not chasing 1 point drops in ph or yellow drop checkers just 1 bubble a second and the plants boomed within a couple of weeks. It was as if they were screaming for just a little bit more co2 than what they were getting. No doubt  I could have achieved the same results using a diy setup just like yours.

On the other hand, if I was to got to the forum page no doubt there would be a post there where someone with some Carlos fandango led light was having co2 related issues with plants and couldn't get their DC to get to the right colour on time. In the case of a pressurised system with solenoid, timer and decent needle valve they have options. With diy there isn't a great deal they can do other than reduce the lighting which defeats the object of buying the light.

You and I had a tank where diy fitted the niche it slots in so I'm all for diy as a cost effective way of adding some co2 and it is quite an interesting part of the hobby introducing people to the benefits. Also accessible to everyone  

BTW I'm loving that Green Nymphea type lilly plant in there. I'm getting me one of those.



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## AverageWhiteBloke

Actually, thinking about it, which I shouldn't really  The maths isn't all that complicated but curiosity got the better of me. Very, very rough science here but going off that graph to reach a specific gravity of 1080 to produce a 10% volume alcohol of wine when fully fermented to dry you would need to add 2.2 pounds or roughly 1kg of sugar to an imperial gallon of water. Using Tescos as an average 1kg of sugar costs 69p and a wine fermented out from a starting gravity of 1080 would produce on average about 1kg of co2 so I guess if you wanted to put a monetary value on it for arguments sake you could say that diy cost about 69p per KG whereas pressurised is about £3 per KG (for me anyway) Jesus Christ I need to get a life


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## AverageWhiteBloke

or would it? that's a 4gallon or 18.9 litre batch so that would have 4kg of sugar in. So it would take 4kg of sugar to create 1kg of co2??? Where's the science people at when you need them. Wish I never started this now, I won't be able to sleep now.


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## Crossocheilus

AverageWhiteBloke said:


> Where's the science people at when you need them.


I'll have a go.
Sucrose is a disaccharide of glucose and fructose, which is broken down and converted to 2 glucose, fermentation of which produces 4 CO2 and 4 ethanol. That ratio is in moles not mass, so is converted by multiplying by the molar masses, giving (I think)
1kg sugar : 0.51kg CO2 : 0.54kg ethanol
Assuming 14% by mass ethanol kills the yeast, then 1kg sugar would need ~4L minimum to ferment all the sugar before killing the yeast.
That's the theory, not sure how much it helps as in reality it won't be 100% efficient and may not be an ideal ratio for long term (2+weeks), stable CO2 etc.


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## Marc Davis

Hahaha. This is the type of blahblahblahblahblahblahblahs that makes newbies reading think "way too complicated for me"


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## Matt @ ScapeEasy

Yeh i sjipped that bit lol... back to simple questions now!... So if I did a small diy co2 on a 220 litre tank,  on a very low 24/7 production would I be alright? If I ran thus into into a bell diffuser would this diffuse less overnight because the waters concentration would be naturally higher?


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## Parablennius

BubblingUnder said:


> From my Home Wine making days I remember that you can buy heater mats for the bottle to control the reaction. Higher temperature for faster reaction & higher CO2 production for a shorter period. Very tasty.


I use an aquarium heater to brew my wine, at 75deg, appropriately enough!


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## Edvet

Crossocheilus said:


> Sucrose is a disaccharide of glucose and fructose, which is broken down and converted to 2 glucose, fermentation of which produces 4 CO2 and 4 ethanol. That ratio is in moles not mass, so is converted by multiplying by the molar masses, giving (I think)
> 1kg sugar : 0.51kg CO2 : 0.54kg ethanol
> Assuming 14% by mass ethanol kills the yeast, then 1kg sugar would need ~4L minimum to ferment all the sugar before killing the yeast.
> That's the theory, not sure how much it helps as in reality it won't be 100% efficient and may not be an ideal ratio for long term (2+weeks), stable CO2 etc.



Big question of-course is how to harvest that ethanol..................................


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## AverageWhiteBloke

Matt @ ScapeEasy said:


> Yeh i sjipped that bit lol... back to simple questions now!... So if I did a small diy co2 on a 220 litre tank,  on a very low 24/7 production would I be alright? If I ran thus into into a bell diffuser would this diffuse less overnight because the waters concentration would be naturally higher?


Yes, additional co2 will improve plant growth, that's a given. The issue is co2 in like a drug to plants in all senses of the word. If you don't want to "complicate" things I'll just say rubisco and leave the googling to you if that's what you want.

In a nut shell though plants adapt to background co2 levels and it takes a couple of weeks for them to adapt to the levels. Once they've had co2 the problem is like a drug when you take it away and the system collapses. The higher the lighting the less margin for error there is and more catastrophic it is. 

Diy is very unstable for all the reasons listed previously and you have no control over that. Once levels start dropping off it takes 24 hours for a fresh batch to get going which is where the two bottles bit comes in. Co2 needs to be as stable and consistent as you can get it a yeast fermentation certainly isn't that but as long as you don't force loads of lighting over the tank you can get away with it. 

On the other hand lower the lighting and leave plants in a non co2 environment and leave them there, once adapted they'll sort themselves out. It's change they don't like even when beneficial.

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## zozo

Have a look at this old journal from 2013..  That little scape ran on DIY CO² with a bell system.
https://www.ukaps.org/forum/threads/starting-point-the-cube-new-cube-rescape.30848/


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## AverageWhiteBloke

Edvet said:


> Big question of-course is how to harvest that ethanol..................................


I find letting it completely ferment out and clear, syphon off, add some pottasium sorbate and mix with any fruit juice of your choice is the best technique. I think they call it hooch in prison. 

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## Marc Davis

Matt @ ScapeEasy said:


> Yeh i sjipped that bit lol... back to simple questions now!... So if I did a small diy co2 on a 220 litre tank,  on a very low 24/7 production would I be alright? If I ran thus into into a bell diffuser would this diffuse less overnight because the waters concentration would be naturally higher?


This is basically all i have. my tank is 200 litres. The bell diffuser is constantly full with the formular


AverageWhiteBloke said:


> Yes, additional co2 will improve plant growth, that's a given. The issue is co2 in like a drug to plants in all senses of the word. If you don't want to "complicate" things I'll just say rubisco and leave the googling to you if that's what you want.
> 
> In a nut shell though plants adapt to background co2 levels and it takes a couple of weeks for them to adapt to the levels. Once they've had co2 the problem is like a drug when you take it away and the system collapses. The higher the lighting the less margin for error there is and more catastrophic it is.
> 
> Diy is very unstable for all the reasons listed previously and you have no control over that. Once levels start dropping off it takes 24 hours for a fresh batch to get going which is where the two bottles bit comes in. Co2 needs to be as stable and consistent as you can get it a yeast fermentation certainly isn't that but as long as you don't force loads of lighting over the tank you can get away with it.
> 
> On the other hand lower the lighting and leave plants in a non co2 environment and leave them there, once adapted they'll sort themselves out. It's change they don't like even when beneficial.
> 
> Sent from my STH100-2 using Tapatalk


Surely having an in tank reservoir/bell of co2 negates the instability?

My bell stays constantly full and overflows with co2 for two weeks. When I see the bell stop being completely full, i.e. bps has dropped off and I re make a batch...the bell is full again within the hour.

Is that making it pretty stable and consistent or am I missing something.


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## AverageWhiteBloke

I would imagine using the bell and keeping it full would be a pretty stable way of keeping the levels  pretty similar. Maybe not the most effective at diffusing with not much of the co2 surface area exposed to water. Probably more problematic if using a diffuser with differing rates of co2 being added daily. 

Do you use a drop checker or do PH drop tests? Would be interesting to see the results. There's a post going somewhere where people are trying using a vacuum in the bell or bottle to see if this draws more co2 into the water that might be an interesting read for you. 

Sent from my STH100-2 using Tapatalk


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## Marc Davis

AverageWhiteBloke said:


> I would imagine using the bell and keeping it full would be a pretty stable way of keeping the levels  pretty similar. Maybe not the most effective at diffusing with not much of the co2 surface area exposed to water. Probably more problematic if using a diffuser with differing rates of co2 being added daily.
> 
> Do you use a drop checker or do PH drop tests? Would be interesting to see the results. There's a post going somewhere where people are trying using a vacuum in the bell or bottle to see if this draws more co2 into the water that might be an interesting read for you.
> 
> Sent from my STH100-2 using Tapatalk


I don't have a drop checker. That will be my next buy for sure.

Forgot to mention. I have two bell diffusers, one each side of the tank. I have 1x 2 litre bottle that splits into two and feeds each bell. Every other Sunday I make a batch like in the video. Pretty minimal effort though I'd say. Tank maintenance is far more demanding and even that doesn't feel like a chore once a week.


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## AverageWhiteBloke

Look forward to seeing the DC results. What are you using for the "bell"? In the video I get the next video play-list popping up right over the top of it so I can't see what it is.


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## Marc Davis

AverageWhiteBloke said:


> Look forward to seeing the DC results. What are you using for the "bell"? In the video I get the next video play-list popping up right over the top of it so I can't see what it is.


I brought 2 of these for a system I tried nearly a year ago. Kept the bell and use them both hooked up to the diy co2.


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## AverageWhiteBloke

Ever fancied the Citric Acid Method? Something I was looking into at one point. You can get the kit for £13 pounds on ebay and you already have the bells. That way you can just switch it on when you need to top up.  Then again, I suppose that defeats the purpose of diy I guess, like I said earlier you can get a dual stage reg and solenoid for sub £40 new, I don't suppose it would matter how precise it was if you just want to fill up the bells. Just be a case of opening and shutting the valve again some days. It will happen though, co2 isn't just addictive to plants, it has the same effect on aquascapers. Just need to convince the missus of that. You won't be the first aquascaper who's lied to TOH about what they paid for equipment  Take my ADA60 H tank and cabinet for example. A steal at £80.00


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## Marc Davis

AverageWhiteBloke said:


> Ever fancied the Citric Acid Method? Something I was looking into at one point. You can get the kit for £13 pounds on ebay and you already have the bells. That way you can just switch it on when you need to top up.  Then again, I suppose that defeats the purpose of diy I guess, like I said earlier you can get a dual stage reg and solenoid for sub £40 new, I don't suppose it would matter how precise it was if you just want to fill up the bells. Just be a case of opening and shutting the valve again some days. It will happen though, co2 isn't just addictive to plants, it has the same effect on aquascapers. Just need to convince the missus of that. You won't be the first aquascaper who's lied to TOH about what they paid for equipment  Take my ADA60 H tank and cabinet for example. A steal at £80.00



Hahaha. I round down by 20 quid on everything. 

Most weeks I spend 20 to 30 quid on tank stuff. But I don't go to the pub or smoke or do anything that costs money really so I'd say it's not much at all. 

I still get the "if you added up all the money you've spent" argument though...which I tell her is rubbish as you could say that about anything.


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## AverageWhiteBloke

Let's be honest here brother, the real reason they get griped is because the tank gets more attention than they do  If I had a pound for every time I got it about my tank being gleaming while there's jobs wanting doing in the house I would treat you to a reg set myself haha 

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## hwscot

This is a very helpful thread, people. Just getting back into the hobby after a long break and the 90L finally got planted up just before Christmas (had a couple of small tanks going for a couple of months before that, growing on some plants, and then added a few platies).
I've started playing with diy CO2 and it's fascinating. First brews have only lasted a few days, but am finding that simply adding more sugar can get it moving again .. I'm assuming I've had what brewers call a 'stuck' fermentation. The difference temperature makes is fascinating . the tank's in a room that is not heated overnight, which I'm finding gives a natural daily pattern of higher and lower CO2 that saves venting overnight. When the rate slows, simply laying a hand against the upper part of the bottle (IRN BRU, naturally) makes a dramatic difference, bubble rate shoots up almost as soon as you touch it.
Started with baker's yeast, which it seems is about the least suitable in terms of tolerating raised alcohol, but maybe suits the situation since it's also more dependent on higher temperatures, so the daily pattern of warming and cooling works nicely. Curious now about combining different yeasts, and how you can maybe develop your own strain. A bit like growing garden plants from seed where over just a few generations you can see how a strain develops suited to your local conditions of soil, climate etc.
Next steps will be a diffuser to replace the airstone, a drop checker, some gelatine, and a jar of Marmite.
I already sense the lure of a pressurised system with full control - maybe the diffuser and DC is me telling myself that's the way I really want to go! But so far the big secret seems to be treating it as a fun thing to play with, with the aim of more consistent rates.


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## si walker

Hi. Yes it is fun. I made the ones with the gelatine at the bottom as well. Some went for four weeks. I experimented too much one day and the fish were really unhappy about it and I never went into it again. I basically had wonderful plant growth but was guilty about the fish being exposed to CO2 24 hours a day.
The expensive wine yeast did not work well at all. Had it hooked up to an internal filter at one point and then a CO2 diffuser.
Have fun but keep an eye on your fish!
Simon


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## Konsa

Hi
In the past when I used DIY CO2 I used a small air line tap on tubing and used to open this at night so the injection is not 24/7.Opening the cap of the bottle will also work.
It wasted a bit of CO2 but its not a biggie and the fish were happy
Regards Konstantin


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## hwscot

si walker said:


> had wonderful plant growth but was guilty about the fish being exposed to CO2 24 hours a day.
> Have fun but keep an eye on your fish!
> Simon


Hi, Simon .. yep, that's a concern. At the moment the tank is growing in so no fish in it yet, but am going to add a drop-checker before fish go in. I'm hoping I can provide some CO2 but not aiming for 30ppm. Under rather than over.


Konsa said:


> In the past when I used DIY CO2 I used a small air line tap on tubing and used to open this at night so the injection is not 24/7.Opening the cap of the bottle will also work.
> It wasted a bit of CO2 but its not a biggie and the fish were happy


Hi, Konstantin .. that's what I did initially, opening the bottle in the evening. But I found that the next morning, production didn't always get going again. Possibly those were my first recipe, which I now realise was low on sugar. For sure some kind of vent valve would be better, and simple to add.

Thanks for the responses, both of you.


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## si walker

Thats a great idea with the tap to close it off at night just a little bit maybe? Not fully as it would have popped in the night! The pressures are amazing actually. Also i just dont trust myself doing that each day. What with the school run and work!! 
Im back on the Liquid Carbo for now.
Keep us updated when you hit that sweet spot with your mixes!


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