Debunked: CO2-Myth --- See tanks without carbon dioxide fertilization

[HarleyK]

Howdy,

Call it what you want: Carbon dioxide is either brilliant marketing or a complete rip-off. Either way, it's a waste of money for most hobbyists. Only extreme-planters keeping demanding species will actually need it.

I ran CO2 on an 80 gal with a professional-grade Dennerle/Dupla combination for almost 2 years (back in 1999/2000). I could not observe significant improvement.

In almost 30 years of planted tanks, I found out that the following matters much more (in order of importance)

1. plant species compatibility with your set-up: Just try out a bunch of different species (see 2.), provide well for them (see 3.-5.), and wait what survives. That's much cheaper than everything else - and gives best success!
   
2. water chemistry (pH, hardness): I do not mess with it, but instead choose species (flora & fauna) accordingly.
   
3. lighting quality: Number, spectrum and age of bulbs. This is where you should spend your money!
   
4. filtration media: i.e. not carbon - my very first lesson learned.
5. mineral fertilization: Substrate and water.
   

Seeing is believing: Below, please find some of my current planted tanks, all of which run without CO2. It works, regardless of tank size:

10 gal




15 gal (cloudy after annual clean-up)



40 gal




75 gal (bare bottom, planted)



220 gal



There is science behind it: Liebig's Law. The one nutrient/factor that a plant is short of, limits growth - even if all other factors/nutrients are overabundant. That one factor is most often quality light, followed by minerals (iron+trace elements). In only very few aquariums you will find that CO2 is that bottleneck. Believe it or not, in my 220 gal, that one limiting factor is nitrate.

HarleyK

 

[Eleven Bravo]

i agree, i went out and drop four hundred bucks acouple months ago on a co2 system, i turned off my co2 one night, and havent turned it back on since, all my plants are still thriving. I keep my lights on for about 6-8 hours a day.

 

[sostoudt]

i dont really call that a myth debunk. alot of co2 articles say co2 is useless with out high lighting and a nutrient rich environment.
btw co2 does work, i have used it in tanks with halides and flourite, it sped up growth rediculously.

btw i was also dosing ferts on top of the flourite


edit: btw im in no way saying co2 injection is necessary to have a planted tank. it just speeds growth in the right environment and allows you to create a carpet effect easier

 

[HarleyK]

i dont really call that a myth debunk.

Post a pic of a flourishing planted tank online, and you will get excess requests about what CO2 system you use ... I call that a myth.

HarleyK

edit: I absolutely agree with your edit

 

[sostoudt]

Post a pic of a flourishing planted tank online, and you will get excess requests about what CO2 system you use ... I call that a myth.

Great if it worked for you. You are in the minority. It'd be great if you could post pics before and after CO2 addition, with details on plant species and water chemistry.

HarleyK

i dont have any pics of it, i lost the tank to black beard algae, i guess thats what i get for not bleach dipping new additions.

it had wysteria, anubias, amazon swords, wendtii. this tank was set up with pressurized co2 i had from a old calcium reactor. it was a 29 gallon high. the lighting was a 175 halide 6500k bulb. flourite substrate, used flourish for dosing. fish were guppies. thought it would be cool to breed them that was until i found out I was "lucky" and they werent caniballistic. population soon exceeded 50. i got the beard algae from a ebay dealer in singapore when i ordered the star grass. star grass arrived dead looking, through it in the tank with out a dip hoping it would live it didnt but the algae did. should have just been patient and wait for the lfs to get it in

anyway ive had planted tanks before non-co2, but they were different in substrate and lighting so i dont think its fair to compare growth rates. but obviously this was alot better

the wysteria grow rediculously fast at the end(had taken over the tank) i was throwing away maybe 4 bunches a week. im considering a bunch about the amount you get when you buy one plant at a petstore.

the anubias was probably the slowest growing plant but i was seeing new leaves every few days.

the sword was budding a new leaf per day.
the crypt leaves dramatically took there submerged leaf forms very fast.

obviously you can see my tank was very high light with over 5 wpg. the substrate was nutrient rich from the get go being that its flourite.then add the waste from all the guppies and bi weekly flourish dosing. and you get one hell of a tank where co2 is the bottle neck.

ofcourse you really need to do everything right because its hard to balance all those factors and not create a huge amount of algae. man when that black beard got in the tank it spread like wildfire. but its ok it gave me a reason to get rid of the guppies i hate those fish now. im gonna try to set up another one again soon, this time no stupid guppies and im gonna go t5. i want glass catfish in that one.

 

[swede]

what you you use for micronutrients and trace elements? I have heard that some treatments give the plants enough to not need CO2. many plants do great without CO2 but i will say that certain plants grow faster with. dosing until said plants reach a certain size is cool IMO

 

[jcardona1]

Only extreme-planters keeping demanding species will actually need it.

this is KEY. i wouldnt really call it a "myth". those that have a clue about planted tanks know perfectly well what can be achieved with and without co2

 

[HarleyK]

Howdy,

it seems like mostly people with CO2 experience post here to rebut my claim, which is perfectly fine. It shows that a few MFKers actually push planting tanks to a new level.

But let's keep it real: Most hobbyists do not need CO2. Just search this forum here for "CO2", and you will get 937 hits. Search it for

• "lighting" (852 hits)
• "fertilizer" (219 hits)
• "species" (282 hits)
• "chemistry" (42 hits)
• "parameters" (101 hits)

and you can easily tell which single factor members consider to be most important. This is wrong on so many levels.

Indeed, CO2 can boost plant growth if everything else is perfect. But that is the exception in our hobby, and you have to prune your plants more often than you have to mow your front lawn. I do not consider that a healthy, natural stage, either.

what you you use for micronutrients and trace elements? I have heard that some treatments give the plants enough to not need CO2.

CO2 is an essential carbon source.
I use Kent Freshwater fertilizers.

HarleyK

 

[velanarris]

this is KEY. i wouldnt really call it a "myth". those that have a clue about planted tanks know perfectly well what can be achieved with and without co2

I also wouldn't call it a myth. I would say that CO2 is the most challenging part of a planted tank as well as being the least important part. That's probably why I was running a 2 bottle DIY for my planted 75 and my planted 29.

 

[Pharaoh]

Very interesting Harley. As a plant noob, I will definitely tak this into consideration.