Which is heavier, O2 or CO2?

[Husmut]

Sorry guys, Im a little bit obsessed by the CO2 thing at the moment!
I ask this question because my DIY reactor releases these tiny bubbles and no amount of re-configuring seems to help.

Out of interest, I put my indicator directly in the stream of the escaping bublets and it went from aqua/green(Nearly good levels of CO2) to blue(no good). Does this mean it is o2 escaping as it is heavier?

 

[Toirtis]

Not sure, but CO2 is far heavier than O2.

 

[krap101]

i thought o2 was heavier. thats why you need to stay near the floor during a fire?

 

[Toirtis]

i thought o2 was heavier. thats why you need to stay near the floor during a fire?

That is to stay out of the toxic gasses, not C02.

 

[krap101]

ic... lol wrong again

 

[greenmaji]

There is a good chance that the CO2 had a good dwell time in your reactor so all your getting out of those bubbles is O2. And from looking at your reactor My guess is that your sponge isnt letting enough gas through forsing it out the top.. maybe it isnt big enough? But it sounds like its working so as they say dont fix it..LOL
By the way have you been able to check your KH and PH to calculate your CO2 level yet.. Id like to here from someone doing DIY CO2 on a 90 gallon!! If you getting good levels you rock at DIY CO2.. even if it does look a little getto!!!

 

[Husmut]

Greenmagi: Changed the set up.....again!!! Now using a gravel vac that is nearly as long as my tank is high. I have plumbed the CO2 into the venturi intake (is that what it is called?) of the pump. Distracts the eye far less than the last one and seems to be more effective. My Kh is at 5 my ph is 7.2. From what I can tell, I have a little way to go, but not much. I would like to get an airstone into the line, but that would involve drilling the lid of the vac and it leaves me with the venturi intake with nothing on it. Any suggestions?

 

[greenmaji]

what do you have at the bottom of the gravel vac tube.. that is what the intake is called.. and if your getting venturi action out of the intake I would stick with that rather than drilling for a airstone.. I would put a sponge like one out of a canister filter in the bottom of the gravel vac tube and fill it with a media to help break up the bubbles, like bio-balls..(one of my LFS sells bio-balls individually you might want to check).
Im wondering were exactly your bubbles are escaping from.. is it the bottom of the gravel vac tube or out of the top of it? do you have the power head attached to pump the water down into the tube with a filter sponge on the intake of the power head?..
And it looks like you only need a .3 drop in your PH left to be in great CO2 territory..
Or a KH like my tapwater!! ROFL..
But from the sounds of things you might need bigger generators to get that drop.. Only time will tell.. How many generators are you running and how big are they? You said you had (2) 3 liter garden sprayers and (2) 2 liter soda bottles right? Im thinking getting two bigger garden sprayers, larger than 4 liters a piece; and getting the other generators out of the mix, would be more effective... Not to mention save you alot of headaches!

 

[spongebob69]

Lets think about this on a molecular level...essentially CO2 is exactly the same as O2 except that it has a Carbon attached. That Carbon atom has a certain atomic weight. Therefore, C02 is heavier by whatever the atomic weight of Carbon is.

 

[krap101]

that sounds right

 

[Husmut]

Thats what I assumed about the weight thing, but like so many things in this world, I wanted to know for sure, not assume! Thanks guys.
Greenmagi: Everything you suggested I am in the process of doing but I anticipate one problem. If I put the sponge in the bottom of the vac (Where the bubbles are escaping from) with bio balls i am worried I might reduce the flow thus reducing the spread of the enriched water. Should this be a concern?
Are you suggesting a pre-filter to stop debris building in the reactor or is there another reason?

 

[greenmaji]

The bio-balls would not slow the flow with the sponge enough to be concerned, in fact that is how most of these DIY reactors are designed.. and the sponge prefilter keeps the inside of the reactor clean and keeps fish and plant muck from being sucked into the power head..
Once you get this done I would write an article or something about it to help people select equipment for this before they start.. sounds like this would have helped you out alot... problem is I havnt seen anything for a tank the size of yours..

 

[Husmut]

Yeah. Would of helped! Also, if I was sensible I would have tried it on a much smaller tank. Oh well! Success is imminent! My readings today are Kh:6, ph 7.2. This puts me at the bottom of the good range. This said, I dont think Ill bother with the balls or sponge at this stage as I am sure it is only O2 escaping. I suspect anyone with this size tank and the right filtration would come close to over saturation with my setup as I have got to this level with a massive trickle filter!

 

[greenmaji]

I have got to this level with a massive trickle filter!

HOLY CRAP! I had no idea you had a wet/dry filter.. grief!

 

[Husmut]

Its hard to explain, but it is part of the hood mold, and runs right along the lenth of the aquarium. It was a matter of sealing off the vents to the filter compartment, slowing down the powerhead and placing the injection stuff up the other end. There is no surface agitation in the aquarium at all

 

[wabyrd]

Lets think about this on a molecular level...essentially CO2 is exactly the same as O2 except that it has a Carbon attached. That Carbon atom has a certain atomic weight. Therefore, C02 is heavier by whatever the atomic weight of Carbon is.

That's exactly right. Oxygen weighs 16 units/volume and carbon weighs 12 units/volume. Therefore, O2 weighs 32 units/volume and CO2 weighs 44 units/volume. Therefore, the same volume of O2 weighs roughly 72% of what CO2 weighs.

 

[greenmaji]

Its hard to explain, but it is part of the hood mold, and runs right along the lenth of the aquarium. It was a matter of sealing off the vents to the filter compartment, slowing down the powerhead and placing the injection stuff up the other end. There is no surface agitation in the aquarium at all

Is your bio-logical media submerged in the water.. if so you dont have a wet/dry and thats not effecting you CO2.. explaining why its able to work..LOL

 

[malkore]

CO2 is heavier than O2, I know for a fact.

 

[greenmaji]

Thats what I assumed about the weight thing, but like so many things in this world, I wanted to know for sure, not assume! Thanks guys.

I think the question was answered and understood...
Sorry guys, Ive hijacked this thread to ask him about the details and help him with his big DIY CO2 project.... 8) 8) 8)

 

[BillD]

Absolutely corect, spongebob69, and well said. I will be in Kingston a week thursday. Are there any good fish stores to check out?