# CO2 diffusion for a yeast-based system



## daizeUK (10 Oct 2013)

I'd like to try a yeast-based CO2 system for my 120L tank and looking into diffusion methods.

I was hoping to use an inline atomiser but I've heard that yeast won't generate enough pressure to make it work.  I assume an inline reactor would have the same problem.

I've been reading other posts and it sounds like a diffuser under the filter intake is the best method.  I have some questions:

Is it better to use a diffuser placed under the filter intake or simply stick the CO2 tube directly into the intake strainer?
I've read that doing this will damage my impeller or make my filter 'burp'.  Anyone experienced this?
I've also read that yeast-produced bubbles have a slime coat which will muck up my equipment, how bad is it?
I've got hard water and worried about small diffuser holes scaling up, any tips for keeping them working efficiently?
Is there any difference between different brands of diffuser, e.g. Fluval vs Neutro vs TMC?


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## NattyAntlers (10 Oct 2013)

1. I run a ceramic diffuser below the spray bars (because of number 2)
2. When I tried this to get the co2 high enough it would cause the filter to burp and also there was a lot of unused c02 left in the filter, it was tricky to use co2 economically.
3. I did run a yeast based system for a short while but through a in tank reactor, worked quit well to be honest, dont know about the slime coat.
4. My tap water is definitely hard, I clean the diffuser in bleach once a month seems to work well, read recently that someone uses de-scaler as well but would like more info on this before I try.
5. the Fluval diffuser has good reviews, its what I use and have no experience of any others, 1 poster did have a lot of problems with theirs and large bubbles escaping around the fitting, I dont know if it was resolved, mine has given me no problems. Buy a second disc to swap when one becomes dirty.


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## jacaranda (10 Oct 2013)

you could try just having the co2 going directly into your filter inlet, a lot of people have theirs this way


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## daizeUK (10 Oct 2013)

Thanks for the answers.

When you say directly into the inlet, do you mean without a diffuser?
I'm thinking that a diffuser might make the bubbles smaller before they go into the filter and cause less 'burping'


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## jacaranda (10 Oct 2013)

You could have a diffuser under the intake or just have the co2 tube going into the intake with no diffuser attached. I don't have a huge amount of experience with this but	 
the co2 tube into the filter intake worked for me. I think it works better with a faster flow rate


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## ceg4048 (10 Oct 2013)

The OP is strongly advised against using a yeast based CO2 method. He is only asking for Trouble....with a capital "T".

Cheers,


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## Lauris (10 Oct 2013)

I was using yeast + sugar nearly for a year and I will never go back.
Just off it.. to research how the system works and to have "something
better than nothing" ..it works.. otherwise it is a hustle to keep it running
with +/- stable co2 levels in tank. 125L - 2 L bottle of mix - changing every
week. Cleaning diffuser every week. Mist from diffuser will be OK 
for first week (if diffuser is new) and every 1st 3 days after cleaning it in
solution weekly.. I'm glad I went through this and no matter what - I will never 
do it again. plants were growing well. Algae too.


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## daizeUK (10 Oct 2013)

Thanks. There are members of my household who are strongly opposed to having pressurized canisters in the house hence yeast is my best compromise at this point.
I will add that the setup will be mostly undemanding plants and low light (30W plus reflectors over 32 gallons, 50cm deep).
Can you explain what kind of trouble you expect I will have?

(edit: I missed your post, thanks Lauris!)

My plan is to start with two 2L bottles each with a check valve fed into a Y-splitter, then a smaller bottle as a froth trap and another check valve.  I hoped that this would smooth out fluctuations.


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## Lauris (10 Oct 2013)

bear in mind, daizeUK,
you will need to design it to turn it off every
eve. And once the mix is fresh you might
need to turn it On and Off more often 
(more likely when you are at home)

My daily routine was - as I'm starting my shift at 7am
I'm home early and my photoperiod started every day
at 4pm. So shortly before I was turning On the DIY CO2
and every night I was turning it off manually. 
for 120L tank 2 x 2 L bottles might be too much.
you cannot add solenoid valve unless you can make
your way to secure the system and once the pressure
in bottles goes too hight when its not supplying tank it
can release the the gas automatically before the bottles
blows up (to be honest I'm not sure how many bars can hold
a plastic bottle    )


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## squid102 (10 Oct 2013)

If you are using undemanding plants and low light then you will have less trouble if you avoid the diy co2 altogether. I, too, started out with yeast based co2. Never again. I must have got every type of algae under the sun at some point. I had much more success with liquid carbon. It's not as good as pressurised co2 but at least it is consistent and does not encourage algae. 

Do yourself a favour and keep the yeast for making pizza dough. It tastes better than diy co2 and is less frustrating.


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## Lauris (10 Oct 2013)

squid102 said:


> If you are using undemanding plants and low light then you will have less trouble if you avoid the diy co2 altogether. I, too, started out with yeast based co2. Never again. I must have got every type of algae under the sun at some point. I had much more success with liquid carbon. It's not as good as pressurised co2 but at least it is consistent and does not encourage algae.
> 
> Do yourself a favour and keep the yeast for making pizza dough. It tastes better than diy co2 and is less frustrating.


 


ohhh.. I do understand how you feel! really! 
(sorry for oftopic)


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## daizeUK (10 Oct 2013)

I've been told that it's best not to turn Yeast CO2 off at night and the livestock will be okay if it's left running.  If that's not okay I could run an airstone at night?
I run my other tank with EasyCarbo and I guess I really wanted to see for myself how much of an improvement I could get with CO2.  I'm planning to use both in this tank.
(I like making pizzas with it too )


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## Lauris (10 Oct 2013)

After changing mix and forgetting it turn off at night in the morning I realised my clown loaches were bearly moving, laying on one side on the ground, bunch of seamise algea eaters very slow and rest of the fishes fairly poisoned. dropchecker yellow as hell. never left the diy ON for the night since... another thing - prepare to clean diffuser once a week. I just left it over night in with hydrogine peroxide. eayh.. and algae.. suffered a lot from it

erutangiS klatapaT now Free


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## daizeUK (11 Oct 2013)

Thanks for the reply, I appreciate the advice.
I've been thinking about your scenario with the poisoned fish.  Your setup was tuned to produce lots of CO2 during the day and then shut off production at night, so when you forgot the CO2 levels went too high.  If a setup was 'tuned' to be running 24/7 then I think this shouldn't be a problem.  A constant low stream of CO2 would build up overnight so that it was green in the morning, then the plants would deplete this during the day to be blue by nightfall.  This might even emulate what happens in nature better.

I'm not afraid of cleaning, I'm used to it   Algae is a concern to me though.


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## ian_m (11 Oct 2013)

If you search around you will find quite a few people having a few successes and mostly major failures with yeast based systems.

I spent ages investigating, thinking about using yeast as simple, easy to DIY, but in the end FE was the way to go and at £10 for 2Kg refill was a no brainer. There are no safety issues with a FE in a home environment other than it's red and will probably never match curtains, sofa's or cushions, but that's what a cupboard is for. If you have real installation problems, the FE can be located remotely, outside, in a garage and CO2 piped to where needed, just do it right or else you will get uncontrollable CO2.

The issues yeast people encountered were
- Very hard to control CO2 reliably. As majority of plant and algae issues are all CO2 related, people were either melting their expensive plants (lack of CO2) or algae coating their expensive plants & tank (variable CO2).
- Very easy to asphyxiate your expensive fish especially at night.
- Needs weekly, possibly daily maintenance.
- Easy to gas your fish/induce algae in the summer when yeast does better.
- Easy to algae coat your plants in the winter when yeast does worse in the cold.
- Be extremely careful with traps to catch escaping yeast ferment. Getting this in the tank due to say knocking bottle over will wipe out all live stock.
- Sealing the equipment. As the equipment will most likely be home made ie coke bottles & tubing, leaks, especially after maintenance is an issue leading melting plants and tank becoming algae farm.

Anyway you may get on better than previous people with yeast, let us know.


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## daizeUK (11 Oct 2013)

Thanks for the tips Ian, that's really helpful.  It's good to know what the pitfalls are that I should watch out for.
I won't be using sensitive plants and I'm prepared to spend a good time tweaking the system before adding any stock.  If I can't get the darned thing to work then I'd rather figure that out before subjecting fish to my mistakes.

The FE route is undoubtedly the best and cheapest but the husband has flatly put his foot down and said no.  I'm pushing my luck having three fish tanks in the house right now so I'm not going to argue with him!


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## ian_m (11 Oct 2013)

One thing someone did to improve reliability of yeast based system was plonk the generator(s) (fizzy drinks bottle) in a bucket of water heated by a 50W aquarium heater.

Nice consistent CO2 generation (using jelly & yeast), good plant growth, including gassing fish at night when air pump failed . Couple of issues water going mouldy in bucket due to being contaminated with yeast yuck.

However one day the heater melted a hole in the bucket, flooded the kitchen and proceeded to start melting everything else under the cupboard .

You could buy a "proper" other half allowable CO2 set, if worried about having a FE at home.
eg http://www.aquaessentials.co.uk/fluval-pressurised-co2-kit-88-p-5378.html
or
http://www.aquaessentials.co.uk/tmc-v2co2-refillable-bottle-567g-p-4442.html
or
http://www.aquaessentials.co.uk/dd-disposable-co2-bottle-with-base-p-650.html
or
	JBL Complete Co2 Kit with Disposable Bottle U402 with Night Time Shut Off  >			JBL Co2 Kits and Consumables  >			Plantcare & CO<sub>2</sub> >			Tropical Aquarium  >			Home >		Aquajardin Limited
or
Aqua Medic Station Co2 Storage Bottle 500g & 2kg. | Swell UK
or if your tank is very big.....
45kg CO2 wheeled fire extinguisher | 45kg carbon dioxide wheeled fire extinguishers

This is my FE, discretely wife friendly hidden away in gap between wall and tank.


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## tim (11 Oct 2013)

I ran a yeast setup for a while, along with the other reasons not too I'll add, my check valve stuck one day from the gunk, needless to say the tubing popped off and sprayed the wall, bed, wardrobe and carpet (was a nano in the bedroom) much to my wife's dismay, I could have put together a cheap pressurised set up with the money I spent on new bedding, flowers, chocolates and carpet cleaner hire


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## daizeUK (11 Oct 2013)

Lol I'd better not let the hubby read these horror stories!

Thanks for the links Ian.  I did consider the JBL M402 system but the initial price plus refilling costs put me off.  I was told that a 500g canister would only last about a month on my 120L tank, at £18 a pop.


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## ian_m (11 Oct 2013)

daizeUK said:


> Lol I'd better not let the hubby read these horror stories!


Do you want me to find the FE & CO2 cylinder blowing up stories as well....

Oh go on then....
http://www.taproot.com/content/wp-content/uploads/legacy/CO2-extinguisher Incident-2.pdf

And there's the Mytbuster's episodes where they put CO2 extinguishers in a fire. Normally got hot and vented via safety pressure release as supposed to and didn't even put the fire out. However putting one in a fire with the safety plug blocked, the cylinder "detonated". It did put the fire out only by blowing the burning logs all over the place. Use Google to find the episodes online.

I am sure much much much much much much more damage is done to homes by the fish tank water not being in the tank  (oh as well as yeast reactors blowing up).

Oh, the guy that supplies me with FE's, in 25 years in the business has never heard of a CO2 cylinder exploding, even when his van full of extinguishers caught fire years ago. He has no concerns about supplying me with them to use at home.


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## Lauris (11 Oct 2013)

yehh.. and you may accidentally drink the mix of yeast+sugar. 
in high concentrations it might be deadly


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## GreenNeedle (11 Oct 2013)

Trying to 'turn off' DIY CO2 setups is asking for trouble.  either in the mix firing up the line when you turn it up or a leak somewhere else.  yeast mixes stink when they're going and there is a lot more pressure in those bottles than you would imagine.

Don't know why someone above said that 2 might be too much for a 120 litre.  I would've suggested 3 bottles for a 125 ltr tank.  You should be overlapping them and using a mixture that is a much slower burner.  No point using 1 bottle and changing it every week as you will have first day inactivity then 3 days of too much then 3 more days of it dropping down again.

Pressurised is the way to go and is much cheaper than DIY.  Add up how much sugar and yeast you are going to buy in 1 year.  You can buy a regulator for that money!!!

However I did pause pressurised and experiment for a bit of fun a few years ago.  Forgive all the picture missing.  They must've disappeared when I sorted out my webspace. lol.

The Yeast Co2 Method - Lighting, CO2, Ferts & Flow - Tropical Fish Forums


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## Lauris (11 Oct 2013)

SuperColey1 said:


> Don't know why someone above said that 2 might be too much for a 120 litre. I would've suggested 3 bottles for a 125 ltr tank. You should be overlapping them and using a mixture that is a much slower burner. No point using 1 bottle and changing it every week as you will have first day inactivity then 3 days of too much then 3 more days of it dropping down again.


 
 I can tell why.. what kind of mixture are you talking about? As with my mixture (400gr of shugar+20g yeast and tiny bit of soda) the
CO2 gas was on the "killing spree" in 1 hour. This pressure was so good as it was keeping the tank in levels around 30mg/l for 1st 2-3 days. I could only
imagine what would happen to my tank if here would be 2 or 3 (omg) bottles. and then it started to drop down.. till the 7th day I was able to get around 18-20 mg/l
the biggest issue was diffuser getting blocked and even the pressure is nice enough there was no mist more.. just small bubbles dissolving in water less ..

just what I have from personal experience using diy for at least 7 months..


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## GreenNeedle (11 Oct 2013)

exactly you should be making the mix weaker, to last longer and keep a more consistent level. a bubble counter should be used to stop the gunk getting to the diffuser as well.

20g yeast is a massive amount!!! I ended up using half a teaspoon I think and that would be something like 3 - 4g


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## Lauris (11 Oct 2013)

I was using bubble counter and non return valves

Once I was low yeast supply (just my lazy a**) for a half or even less as usual..
this is what I ended up with..

If the mix was weak it really did not give any results in first
day and also the levels were low on 2nd and 3rd and much less after..


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## GreenNeedle (11 Oct 2013)

I remember in the good old days of the nutrafin kit it was 3/4 teaspoon sugar max.  They were only 500ml or so containers though if I remember rightly.

A lot of the asian DIY'ers who make their own filters and lights seem to have very good results from slow burners.  But then those guys seem to be able to work miracles with anything aquatic. lol


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## squid102 (11 Oct 2013)

daizeUK said:


> I did consider the JBL M402 system but the initial price plus refilling costs put me off.  I was told that a 500g canister would only last about a month on my 120L tank, at £18 a pop.



If you are close enough, pop down to Guildford Calor Gas for a 6.35kg pub co2 bottle. Not sure of the current price but last year they were £18. That will last you all year.


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## daizeUK (11 Oct 2013)

Good lord, but where would I put it?!

SuperColey I read your yeast experiment article already and it was very interesting.  I think it was your article that actually made me want to give yeast a try.  A pity the pictures are missing.  I noticed that you recommended changing all three bottles every week, did you ever try this yourself or did you stick to one a week?


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## GreenNeedle (11 Oct 2013)

A long time ago now.  For the setup I was using I ended up putting 1 teaspoon+400g sugar.  bottles filled up with water and change 1 a week.  This wasn't for 30ppm though.  was probably closer to 20ppm.  changing each bottle on different days of the week i.e. bottle 1 on tuesday, bottle 2 on thursday etc I did half teaspoon+400g sugar and that was pretty much on 30ppm

however 3 bottles x 400g of sugar = 1.2kg.  1kg of sugar = 85p.  52 x1.2x .85 = £53 a year just on sugar.  Add in the yeast.  Add in any repairs to the setup etc.  Pressurised is cheaper within 2 years and much less hassle.


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## AverageWhiteBloke (12 Oct 2013)

I messed around with diy yeast for about a year with various results and various algae. Looking back now if gas bottles weren't an option I would plump for liquid carbon only system.  
In my quest to get co2 levels right and stable which, undoubtedly is the hardest part of the hobby, I find myself looking at small things like the diffuser losing effectiveness through clogging. The general flow reducing in the actual tank over time because of the filter. Co2 not getting round the plants because of too dense planting and also the Reg and needle valve not being the most stable because I went for the budget option. 
All this is with pressurised co2! Diy yeast adds a myriad of extra problems to the mix. Leaking pipes, stuck ferments and rather than variations on a week timescale changes to co2 production happen within hours. Having made wine for many years I found there is also different stages to the process. Aerobic which is vigorous and anaerobic which is slow. Temperature, acidity due to co2 the alcohol content all cause the production of co2 to change. In the world of co2 change is not good.


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## Mattlamb09 (31 Jul 2014)

Hi, I'm new to this forum and I only learnt about the CO2 requirement for making pizza dough the other day, I'm interested to learn how this is used and how much CO2 you need?  Is there a danger of a CO2 leak which could cause harm to the human body?

If you anyone could give me information on this it would be greatly appreciated.

Thanks


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## NattyAntlers (31 Jul 2014)

Hi
Lots of great advice here if you want to use CO2 to grow aquatic plants, if you want to make pizza dough then maybe this site would be of more interest http://www.pizzamaking.com/forum/

Yes CO2 can be very harmful if you have enough of it in a confined space.


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## ceg4048 (31 Jul 2014)

Yes, if you put a plastic bag over your head and duct tape it tightly to prevent leaks you will easily suffocate in that confined space.
On the other hand, CO2 is used as a fire extinguisher, so, like many things (electricity comes to mind) the irony is that it can either kill you or save your life, depending on the application.

The more relevant danger is that CO2 is highly toxic to fish and to other aquatic fauna, so the use of it is an art form as well as a science.

Please navigate to the Tutorial Forum and read about the techniques of CO2 application.

Cheers,


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