# How much co2 do I need for my planted tank



## fleshwound (Jan 26, 2011)

Ive got a co2 bottle used for beer and I have it hooked up to my tank with a fluval 20g diffuser. Im not sure though how much co2 I should be diffusing into my water I dont want to kill my fish. The box said to turn the gas on and fill till the difusser filled up then turn it off. Does anyone know if I should be leaving it on or not. Should I dose the tank once a day, all the time I dunno? This is for a 29g tank... Heres some pictures


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## BradC (Dec 22, 2010)

The first thing you will need to pick up is a drop checker and 4dkH solution.

The drop checker will tell you when you have safe/good amount of CO2 in the water.

Once you get that you will need to supply CO2 to your tank the whole time you have the lights on (everyday). You could leave it on 24/7 but is worth it to get a solenoid. Solenoid is a device that can be plugged into a timer and will shut off your CO2 when it is not needed (at night, lights out)

Good luck


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## fleshwound (Jan 26, 2011)

Ok, right now I turn my co2 on till my diffuser fills up, turn it off and let it disolve into the tank. It doesnt take long for it to disolve maybe an hour or 2 and both chambers are empty... I do this once or twice a day so its at least getting some co2... Im also dosing iron supplement, only problem is im pretty sure I got the worst kind of gravel I could have... Pacific gravel #5 I guess its for saltwater tanks? it was sold as freshwater to me, I had no idea at the time... Sorry if thats a little off topic, and wow Im a Brad C also? Weird


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## Darkblade48 (Jan 4, 2008)

The particular diffuser that you have is a passive diffusion type diffuser. I would not recommend it for CO2 diffusion as it is very inefficient, and will lead to spikes in your CO2 concentration.

You will notice that after about 2 hours, the CO2 is gone, and you will need to refill the diffuser chamber with CO2, necessitating that you be around to control the CO2 cylinder.

A much better method of diffusion is either to use a glass diffuser with a ceramic disc, or to use an inline diffuser. For more information regarding diffusion methods, please take a look at the CO2 article that I have written (it is linked in my signature).


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## rstampa (Jan 29, 2017)

You only turn off your co2 when the lights go out and on when light are turned on. The diffuser should continuously bubble while the co2 is on. At least 6 hrs or more. 
You must be reading something wrong in the instructions. Don't turn it off when the diffuser is full. Let the co2 run as suggested above.


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## Dman911 (Nov 24, 2016)

rstampa said:


> You only turn off your co2 when the lights go out and on when light are turned on. The diffuser should continuously bubble while the co2 is on. At least 6 hrs or more.
> You must be reading something wrong in the instructions. Don't turn it off when the diffuser is full. Let the co2 run as suggested above.



There are many different types of diffusers his is a chamber that you fill and then shut off. He cannot leave it running as there is no reliable way to regulate the co2 for this setup. He needs a needle valve at the absolute min and preferably a bubble counter, solenoid ceramic diffusor in order to leave it running like most do for the full lighting period.

Dan


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