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How To: DIY co2. Secret Formula

AverageWhiteBloke said:
Where's the science people at when you need them.
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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.
 
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?
 
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.
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I use an aquarium heater to brew my wine, at 75deg, appropriately enough!
 
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.
Click to expand...

Big question of-course is how to harvest that ethanol..................................:woot::what::D
 
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?
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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
 
Edvet said:
Big question of-course is how to harvest that ethanol..................................:woot::what::D
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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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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?
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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
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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.
 
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.

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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
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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.
 
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.
 
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 ;):D Take my ADA60 H tank and cabinet for example. A steal at £80.00 :rolleyes:

 
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 ;):D Take my ADA60 H tank and cabinet for example. A steal at £80.00 :rolleyes:

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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.
 
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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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.
 
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
 
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
 
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
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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
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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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