Very confused about CO2

[hulkamaniac]

I must confess I'm very confused when it comes to CO2. I just planted a tank recently and right now I've got two swords, anachris and hornwort. The hornwort all started dieing off for some reason, but it's starting to come back and the other plants are fine. I've got about 2 wpg on the tank and I hear several people saying that's the level where you need CO2. I'm reluctant to add anything to the tank if I absolutely don't have to. Adding to this, I hear about people adding CO2 injectors vs CO2 diffusers. If I decide to add CO2 do I need one or the other or both? Do I really need CO2 at all?

 

[Lonewolfblue]

You are at the line of yes and no. If all's going fine, and you don't have an algae problem, then you should be fine without it. As for the CO2, CO2 injection is just a broad term for putting CO2 into the tank. CO2 diffusers and CO2 reactors are the physical tools used to put the CO2 into the water. The CO2 reactors are generally more efficient, and diffusers are passive. Then you need the source, which you can go DIY with 2L bottles with all the ingredients, or a CO2 tank. Then the only other thing is a ph controller, which isn't needed, but allows you to maintain a particular CO2 level in the tank by maintaining a particlar ph level. So, if your tank is doing fine at 2w/g, and no algae problem, then you probably don't need it. And if you did, you could dose Flourish Excel instead, if it's a smaller tank. It is also another carbon source, rather than injecting CO2.

 

[hulkamaniac]

Let me make sure I've got this right then. The reactor is the bottle that sits on the ground, shelf, top of the tank, wherever. The diffuser is the the thing that attaches to the reactor and actually carry's the CO2 into the tank?

I'm actually considering putting together a DIY reactor. I am seeing some algae problems that I never had in the 55 gallon. This may be because the hornwort I had in there all died. It generally grows fast enough that I think it pretty successfully competes with the algae for nutrients.

 

[Purrbox]

The term reactor can be used interchangably to refer to either the bottle used to generate CO2 or the device used to inject CO2 using powered diffusion. Unfortunately this causes confusion for most people when they are first learning about DIY CO2.

 

[hulkamaniac]

The term reactor can be used interchangably to refer to either the bottle used to generate CO2 or the device used to inject CO2 using powered diffusion. Unfortunately this causes confusion for most people when they are first learning about DIY CO2.

Excuse me. My brain just exploded. I'll be picking up the pieces over here in the corner.

 

[Lonewolfblue]

What I mean by diffuser is like a glass diffuser or airstone. Those are passive. A reactor is like a cylinder bubble ladder where the bubbles follow a path, and there's a powerhead blowing water the opposite direction. These are 2 ways of putting CO2 into the water. The CO2 tank is what sits on the ground or under your tank. So basically, the diffuser and the reactor both do the same job, just reactors are more efficient.

The CO2 bottle provides the CO2.
The regulator attaches to the bottle to regulate the flow.
The CO2 goes through the CO2 tubing to the reactor or the diffuser, whichever you use.

I hope this clears it up some.

 

[hulkamaniac]

It does somewhat. A DIY model would involve the pop bottle w/the hole for the hose. Then the (tubing) then runs into the tank and the CO2 goes inot the water through and airstone right?

 

[Lonewolfblue]

You are correct. The airstone is the diffuser/reactor. That is where the diffusers or reactors go. They diffuse the CO2 into the water. Also, in between the Bottle and the diffuser, you might want to add in one of those valves that only allow one direction. You don't want to accidently flush tank water back into the bottle or flood the floor under the tank. But yes, you have it correct.

Then of course, you want to use silicone to seal around where the tube goes through top of the pop bottle.

Then, if you want added protection, get a 2nd pop bottle, and run the tube from the first bottle into the 2nd bottle. Then from a 2nd hole in the top, run a tube from the 2nd bottle to the tank. This way, if for some reason there is an accident, you won't get a tank full of your ingredients if an accident occurs. It will just end up in the 2nd bottle. A safety precausion.

 

[hulkamaniac]

If I set the bottle on the floor or in the stand under the tank, then the only thing I'll have to worry about is the tank water flooding into the bottle right? That's easily remedied by a check valve. How would the contents of the bottle wind up in the tank?

 

[Purrbox]

The biggest problem with placing the bottle on the floor is that the bottle will need to build up more pressure to force the CO2 into the tank. In some situations this is too much and it appears that the bottle isn't producing any CO2. Having too long of tubing can cause similar issues.

The mix in the bottle can make it's way into the tank if the bottle is filled to full and/or gets shaken causing the mix to foam up rapidly.

 

[Lonewolfblue]

The biggest problem with placing the bottle on the floor is that the bottle will need to build up more pressure to force the CO2 into the tank. In some situations this is too much and it appears that the bottle isn't producing any CO2. Having too long of tubing can cause similar issues.

The mix in the bottle can make it's way into the tank if the bottle is filled to full and/or gets shaken causing the mix to foam up rapidly.

That's the exact reasoning, it may excessively foam. The extra bottle is just a safety measure, IMO.

 

[malkore]

I always try to use the term 'generator' for the bottle that sits on the floor that actually produces CO2 gas.

 

[Lonewolfblue]

I always try to use the term 'generator' for the bottle that sits on the floor that actually produces CO2 gas.

I forgot about that term, yes. lol...

The DIY bottles as well as the CO2 tanks are the generators. They produce the CO2. The DIY uses ingredients to produce CO2, where a CO2 tank is compressed CO2 liquid.