CO2 systems
Doug
Member, Classifieds Posts: 2,371
Hey One and all,
I have been doing a lot of looking into CO2 systems and the different options avaliable. I was thinking that it would be a good idea to have a sticky thread basically going through all the information on CO2 systems and what they can do for you.
As i understand it, and by all means correct me if i'm wrong, CO2 is used in aquariums that are well planted and the amount of disolved CO2 is not enough to keep the plants going. From my research standard CO2 concentration in a normal aquarium with no air being put into the water (airstone etc) is about 2-5% roughtly about the same as the air that we breathe. Normally surface agitation (rippling from water outlet) is enough to keep the CO2 and O2 is good enough ammounts for most uses, for more fish you need to bubble more air into the water, for more plants you need to bubble more CO2 into the water.
Here is a pic of my 4fter with no CO2 just so you can get an idea of what sort of plant levels you can achive without CO2
not the bist pic but you get the idea.
the plant life in my tank stalled so i started using a chemical carbon additive the increase the amount of disolved CO2 avaliable to the plants, well while not techincally being CO2 is facilitates the same job. I used Seachem Florish Excel, a chemical that you will see alot on this site simply because it does so many things. Firstly, it increases the level of disolved CO2 to about 20% meaning that there is much more avaliable to plants and they will take off. Secondly, it has a brilliant side effect of killing off algae, and can be used to kill of the dreaded Black algaes (Beard and brush). Since i started using this stuff (in congunction with seachem Florish as a fertilizer) the plants have taken off. but i still want more, i want the entire bottom of my tank to be planted.
So the next step is CO2 systems. these systems get the CO2 upwards of 90% in the tank, some of the better ones will maintain it at 100%. they do this by bubbling CO2 into the water using either a powerhead or some for of airstone (can be very complex). this is done during the day as plants only use CO2 during the day, at night some people switch to using a standard bubbles setup to get O2 back into the water, the jury is still out on this and i have been told good and bad thiongs about this. as far as i can tell, as long as the rippling on the surface keeps enough O2 in the tank for your fish, its plently for your plants, just remember at night your plants use O2 as well, so it may pay to check your fish in the morning before the lights come on to see if they are gasping as that may indicate low O2. As far as i understand there are 4 basic options for these things and they all have advantages and problems.
1) DIY CO2 systems: these basically involve producing CO2 with yeast fermenting and bubbling that gas into the tank. This is great becasue it is really cheep and will get the CO2 into the tank. However, you must be extremely careful. CO2 forms carbonic acid in water and if you bubble too much in your PH will bottom out killing more of your fish and plants. So the use of these CO2 systems must be with a vigalent eye so that your pH doesnt drop too far. as there is no way or regulating these systems you need to have a tap to be able to turn the gas off in need be.
2) Basic manual CO2: these systems are basically a CO2 source (bottle or fermentation) atached to a powerhead. These systems are esentially the same as DIY setups however, the releace of CO2 is more controlled and therefore the pH problems are slightly reduced, you still need to keep a solid eye on it all tho. your pH, kH and CO2 levels are all linked and need to be tightly controlled.
3) semi-automated systems: These systems use a bottle of CO2 and an automatic dispenser to ensure that there is a constant level of CO2 going into the water. this system is miles ahead of the previous two as the level of CO2 in the tank is more tightly controled by the system. however, it is not perfect. The level of CO2 used by plants changes during the day, starting off low and increasing to a peak about 2-3 hrs before sunset (lights out) and then tailing off. The constant feed of CO2 means that for the moring there is excess CO2 and the pH will drop, however, as the need for CO2 increases it surpasses the supply and the pH will rise, givng a constant fluctuation of CO2. and the system MUST be turned off over night as plants don't use CO2 over night and the pH will drop killing all. these systems are starting to get expensive, all the hardware is getting up around $800
4) Fully-automated systems: The Bees knees of CO2 systems. they use a probe to test the pH and constantly adjust the CO2 imput to match the amount being used by the plants. these systems do it all by themselves and whats more, as the prob tests pH it also gives you are warning system if you pH is doing something funny. however, they are not cheep, decent systems will set you back more than the tank itself, upwards of $1800. However, they are good for about 10 years apart from the bottle that needs to be refilled about once a month.
So, depending on budgets there is a CO2 system out there for all. basically, the more you spend the less you have to worry about it going worng. I myself am poor and will stick to using the chemical additives (florish excel) but one day when im rich and famous (how many times have you said that when talking about your fish tank lol) i'll get the fully automated one, im too forgetful for the basic ones and the semi-automated one will cause the pH to fluctuate and some of my fish wont like that too much and will prob stop breeding.
anyway, hope that helps, if any of this is off the mark please correct me as i'm still trying to figure it all out.\
Doug
I have been doing a lot of looking into CO2 systems and the different options avaliable. I was thinking that it would be a good idea to have a sticky thread basically going through all the information on CO2 systems and what they can do for you.
As i understand it, and by all means correct me if i'm wrong, CO2 is used in aquariums that are well planted and the amount of disolved CO2 is not enough to keep the plants going. From my research standard CO2 concentration in a normal aquarium with no air being put into the water (airstone etc) is about 2-5% roughtly about the same as the air that we breathe. Normally surface agitation (rippling from water outlet) is enough to keep the CO2 and O2 is good enough ammounts for most uses, for more fish you need to bubble more air into the water, for more plants you need to bubble more CO2 into the water.
Here is a pic of my 4fter with no CO2 just so you can get an idea of what sort of plant levels you can achive without CO2
not the bist pic but you get the idea.
the plant life in my tank stalled so i started using a chemical carbon additive the increase the amount of disolved CO2 avaliable to the plants, well while not techincally being CO2 is facilitates the same job. I used Seachem Florish Excel, a chemical that you will see alot on this site simply because it does so many things. Firstly, it increases the level of disolved CO2 to about 20% meaning that there is much more avaliable to plants and they will take off. Secondly, it has a brilliant side effect of killing off algae, and can be used to kill of the dreaded Black algaes (Beard and brush). Since i started using this stuff (in congunction with seachem Florish as a fertilizer) the plants have taken off. but i still want more, i want the entire bottom of my tank to be planted.
So the next step is CO2 systems. these systems get the CO2 upwards of 90% in the tank, some of the better ones will maintain it at 100%. they do this by bubbling CO2 into the water using either a powerhead or some for of airstone (can be very complex). this is done during the day as plants only use CO2 during the day, at night some people switch to using a standard bubbles setup to get O2 back into the water, the jury is still out on this and i have been told good and bad thiongs about this. as far as i can tell, as long as the rippling on the surface keeps enough O2 in the tank for your fish, its plently for your plants, just remember at night your plants use O2 as well, so it may pay to check your fish in the morning before the lights come on to see if they are gasping as that may indicate low O2. As far as i understand there are 4 basic options for these things and they all have advantages and problems.
1) DIY CO2 systems: these basically involve producing CO2 with yeast fermenting and bubbling that gas into the tank. This is great becasue it is really cheep and will get the CO2 into the tank. However, you must be extremely careful. CO2 forms carbonic acid in water and if you bubble too much in your PH will bottom out killing more of your fish and plants. So the use of these CO2 systems must be with a vigalent eye so that your pH doesnt drop too far. as there is no way or regulating these systems you need to have a tap to be able to turn the gas off in need be.
2) Basic manual CO2: these systems are basically a CO2 source (bottle or fermentation) atached to a powerhead. These systems are esentially the same as DIY setups however, the releace of CO2 is more controlled and therefore the pH problems are slightly reduced, you still need to keep a solid eye on it all tho. your pH, kH and CO2 levels are all linked and need to be tightly controlled.
3) semi-automated systems: These systems use a bottle of CO2 and an automatic dispenser to ensure that there is a constant level of CO2 going into the water. this system is miles ahead of the previous two as the level of CO2 in the tank is more tightly controled by the system. however, it is not perfect. The level of CO2 used by plants changes during the day, starting off low and increasing to a peak about 2-3 hrs before sunset (lights out) and then tailing off. The constant feed of CO2 means that for the moring there is excess CO2 and the pH will drop, however, as the need for CO2 increases it surpasses the supply and the pH will rise, givng a constant fluctuation of CO2. and the system MUST be turned off over night as plants don't use CO2 over night and the pH will drop killing all. these systems are starting to get expensive, all the hardware is getting up around $800
4) Fully-automated systems: The Bees knees of CO2 systems. they use a probe to test the pH and constantly adjust the CO2 imput to match the amount being used by the plants. these systems do it all by themselves and whats more, as the prob tests pH it also gives you are warning system if you pH is doing something funny. however, they are not cheep, decent systems will set you back more than the tank itself, upwards of $1800. However, they are good for about 10 years apart from the bottle that needs to be refilled about once a month.
So, depending on budgets there is a CO2 system out there for all. basically, the more you spend the less you have to worry about it going worng. I myself am poor and will stick to using the chemical additives (florish excel) but one day when im rich and famous (how many times have you said that when talking about your fish tank lol) i'll get the fully automated one, im too forgetful for the basic ones and the semi-automated one will cause the pH to fluctuate and some of my fish wont like that too much and will prob stop breeding.
anyway, hope that helps, if any of this is off the mark please correct me as i'm still trying to figure it all out.\
Doug
Comments
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Hi, regarding the automated system, you can get many of the components at pretty decent prices. I recently set up a computerised pH control system (with a dual output regulator, two computers, two solenoid valves, and two reactors to control two tanks to a constant pH of 6.5) for the following prices:
1 x 4L Cylinder - $200 delivered full - Keg King
1 x Dual Output Regulator - $70 - Keg King
2 x Solenoid Valve - $220 - Aquamedic
2 x CO2 reactor - $40 - Guppys Aquarium Products
2 x pH Computer - $240 - Guppys Aquarium Products
Total - $770 for full automation of two tanks. I reckon that figure would drop to $600 for a single output system. At first it seems like a lot, but if you have delicate livestock, it's worth the investment. I lost a couple of batches of shrimp that would have sold for a couple of thousand dollars, and since getting the system, I haven't had any losses. For me, I see it as having paid for itself many times over.
Cheers -
Hey Ekul,
How well do the Guppies pH computers work? I have been looking at their site and it seems that i could get a fully automated system for $469. The only thing that concerns me is the quailty of the hardware...whats your experence with this stuff?
Doug -
hi, what do you guys say to CO2 tablets. i have 120l (i think) and my plants havnt' been looking good for a long long time. i have two lights at 20w (60cm long) one blue and one in the yellow/red ( i think).... i want my platns to grow large and leafy, atm they are weak and not very pleasant looking. help my Doc Phil. lol.
josh.
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hrmm, i have spoken to many people and no one really mentioned them. i imagine they would be a quick dose of co2 but the effect would be tempory. I would try upping the light and adding some seachem florish excel.
would be interesting to hear some testimonials of people who have tried them as they seem quite cheap. -
Hi Doug,
You do not need to run the CO2 injection system 24/7. Plants only require CO2 when they convert light into sugar and other organic nutrients. Otherwise, like all other living organisms they consume oxygen. I use Sera CO2 Plant Care Set which retail for about $45-60 (the refill tabs cos about $10-15).
"Doug" wrote:hrmm, i have spoken to many people and no one really mentioned them. i imagine they would be a quick dose of co2 but the effect would be tempory. I would try upping the light and adding some seachem florish excel.
would be interesting to hear some testimonials of people who have tried them as they seem quite cheap. -
"mondeo79" wrote:Hi Doug,
You do not need to run the CO2 injection system 24/7. Plants only require CO2 when they convert light into sugar and other organic nutrients. Otherwise, like all other living organisms they consume oxygen.
Indeed, infact doing so will prob kill all the fish and plants as the pH will drop dangerously low. CO2 + H2O = H2CO3 (Carbonic acid)
thats why i would be careful with the tablets...but i imagine that the people who develop them would have already thought of this and compensated for it.
Good to hear they work, do they need that kit thing? -
Hi Doug,
The Sera CO2 tablet is a controlled released system that releases 100ml (2500 bubbles) of pure CO2 over a few hours. You use a tablet every third day for a 90L tank or every second day for a tank that is between 120-170L. I use two tablets every second day for my 55 gal tank which has 3 Amazon Swords, 4 small Anubia and a java fern.
The kit helps... cos it has the most important thing you need. The instructions and dose guide!!!!!"Doug" wrote:"mondeo79" wrote:Hi Doug,
You do not need to run the CO2 injection system 24/7. Plants only require CO2 when they convert light into sugar and other organic nutrients. Otherwise, like all other living organisms they consume oxygen.
Indeed, infact doing so will prob kill all the fish and plants as the pH will drop dangerously low. CO2 + H2O = H2CO3 (Carbonic acid)
thats why i would be careful with the tablets...but i imagine that the people who develop them would have already thought of this and compensated for it.
Good to hear they work, do they need that kit thing? -
Well, after all my time looking into these systems i finally settled one one and bought it.
I bought a semi-automated kit from a company called Aquascape Design which has .82ltr cylinder, twin guage regulator, solinoid, hose, needle valve, glass diffusor, co2 indicator and a buch of clips. thats cost me about $375 delivered full.
From there i bought a pH controler of ebay for $130.
All up it cost me $505 for a fully automated system.
its been running on the tnk now for about 2 weeks and i have already had to remove some of the faster growing plants becasue they were just growing too fast, like 3ish cm a day.
check the thread in the photo gallery section called CO2 diaries, i'll have progress pics as well as some pics of the system.
Hope this thread helps people get into the wonders of CO2, not nearly as expensive as my initial information made out. -
Ok
Spotted the final hole in the CO2 situation.
Be careful when using CO2! it is excellent but it has so many hidden issues that i stress that you need to do research before setting it up. I thought i had all the bases covered and had my automated system running for over 7 months before a big issue came up and resulted in me loosing over $200 worth of fish <!-- s
--><img src="{SMILIES_PATH}/icon_cry.gif" alt="" title="Crying or Very sad" /><!-- s -->
My tank is by a window which is open to get better light for the plants. however, i also live in Adelaide, which does from time to time heat up to over 40 degrees. Not wanting to cook my fish (or me for that matter) i closed the curtain behind the tank to keep everything cool. But by removing the sunlight i reduced the ammount of O2 being produced by the plants (normally you can see streams of bubbles rising off the plants). Overnight, all the fish that couldnt breathe air from the surface died as the O2 levels dropped too low.
In order to prevent this happening again i hooked up an airstone to run at night (coming on hour after lights out and stopping an hour before lights on). but this only resulted in more deaths owing to pH swings caused by the air displacing the CO2 in the water at night.
So, after much heartache and loss i have finally come to the point of having the right ballance. I have the airstone in at night still but it only runs 15 mins every 1.5 hours, enough to get some O2 into the water but not really long enough to increase the pH by more that 0.2. this changeswith the additionon of plants/fish and there have been many late nights and midnight alarms to get me up and check the pH, fish etc to make sure its all running well.
My advice to those wanting CO2 is to really think about it, it is a lot of work and you are playing with fire. butthe results can be simply beautiful <!-- s:cheers: --><img src="{SMILIES_PATH}/icon_cheers.gif" alt=":cheers:" title="Cheers" /><!-- s:cheers: --> -
Wow Doug i have just read all of this and its fantastic information, I didn't really know to much about CO2. I am sorry to hear about your fish that you lost, <!-- sthumbdown: --><img src="{SMILIES_PATH}/icon_thumbdown.gif" alt="thumbdown:" title="thumbdown" /><!-- sthumbdown: --> I can't believe how dedicated you are to your fish and tanks I would have trouble waking up during the night to check PH levels, but my fish are no where near as valuable as yours (well maybe sentimental value)
Once again Great Info. <!-- s:dance3: --><img src="{SMILIES_PATH}/dance.gif" alt=":dance3:" title="dance3" /><!-- s:dance3: -->
Andy <!-- s:fish: --><img src="{SMILIES_PATH}/icon_fish.gif" alt=":fish:" title="fish" /><!-- s:fish: --> -
Ok figured i would update this thread as it has been a while and i am bursting with new information.
Firstly, Some of the things i have mentioned above are slightly missleading, follow the course of action and you will will still have a good outcome but my reasoning was wrong <!-- s:( --><img src="{SMILIES_PATH}/icon_sad.gif" alt=":(" title="Sad" /><!-- s:( -->
CO2 doesn't remove O2 from the water, at least not in any major way. the effect is minimal. So looking at why fish would be gasping when you CO2 system is running hard there are several reasons but the big one is this...The concentration of CO2 in the water is approaching that of the blood in the fishes gills...there for the fish cant get rid of the CO2 in its body, Similar to throwing a blanket over your head and sealing yourself in. see how long it takes before you are gasping for air! so make sure you know what the CO2 concentration in your tank is...here is a rough guide to help.
<!-- m --><a class="postlink" href="http://www.aquarticles.com/articles/plants/Podio_CO2_KH_PH_Chart.html">http://www.aquarticles.com/articles/pla ... Chart.html</a><!-- m -->
secondly, there are different methods for getting CO2 into the water. The cheepest is bubbling it in with an airstone. This method is very wasteful as much of the CO2 is wasted when the bubbles reach the surface. Hext is the glass diffusers you can get with some kits. These work in a sililar way to airstones but the bubbles are much finer and there for disolve faster, meaning less is waster but there is still some wasted at the surface. The next system is a CO2 reactor. This uses mechanical force to disolved the bubbles into the water. These range in price from under $20 to well over $300 so be carful on how you spend your $$$. The more sxpensive ones use a powerhead or impeller to break up the bubbles where as the cheeper ones use the outflow from your canister or powerhead to move an impeller to smash up the bubbles. both seem to work equallly well and my $18 job works great as long as I keep it clean.
Hope this helps
If you want some more in depth reading then here are some solid threads...ensure you read the entire thread as ideas are put forward then disporved later.
<!-- m --><a class="postlink" href="http://www.thekrib.com/Plants/CO2/night.html">http://www.thekrib.com/Plants/CO2/night.html</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.aquariumlife.com.au/showthread.php?t=23264">http://www.aquariumlife.com.au/showthread.php?t=23264</a><!-- m --> -
Thanks for all the info Doug <!-- s:thumbright: --><img src="{SMILIES_PATH}/icon_thumright.gif" alt=":thumbright:" title="thumbright" /><!-- s:thumbright: --> <!-- s:thumbright: --><img src="{SMILIES_PATH}/icon_thumright.gif" alt=":thumbright:" title="thumbright" /><!-- s:thumbright: --> <!-- s:thumbright: --><img src="{SMILIES_PATH}/icon_thumright.gif" alt=":thumbright:" title="thumbright" /><!-- s:thumbright: -->
A lot of helpful info there <!-- s:D --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt=":D" title="Very Happy" /><!-- s:D --> -
Wow Doug..Great info...& easy to understand.
Thanks for that.
"I'm a Doug Addict" 
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Yeah good stuff once again Doug,correct me if im wrong but an air stone only creates a larger surface area,not actually putting more oxygen into the water?Cheers :-h
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yep, you are right, but in doing so it allows for maximum gas exchange between the air and the water
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Hey, that was great thank you doug, the co2 chart is a great help.
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