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Discussion Starter · #1 ·
I just set up my first CO2 system, it's DIY paintball. My diffusor is in an area of the tank that doesn't have much water movement. Just wondering do I need to move it to an area with good movement, or will CO2 diffuse throughout the tank just fine w/o much movement? (My drop checker isn't here yet so I can't look for myself)
 

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Good flow/circulation in your tank is essential for dispersing nutrients evenly through out the tank - this includes CO2 along with fertz.
Dead spots will likely lead to algae issues. CO2 in paricular will off gas much quicker if it is simply rising to the surface and not being moved around with in the tank.
 

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good flow/circulation in your tank is essential for dispersing nutrients evenly through out the tank - this includes co2 along with fertz.
Dead spots will likely lead to algae issues. Co2 in paricular will off gas much quicker if it is simply rising to the surface and not being moved around with in the tank.
+1.
 

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Dissolved CO2 travels very slowly through water on its own. Only 0.0016mm per second!

And water in direct contact with leaves also moves far slower than free-flowing water in open areas of your tank; not only does the leaf block circulation, but the water itself behaves almost as if it was sticky.

So if you could actually see CO2 distribution in your tank, you'd see a thin layer on each leaf, about 1-2mm, where CO2 is much lower. The plant is consuming it faster than it can be replaced by either diffusion or water movement. This is known as the Prandtl Boundary.

You cannot eliminate the boundary completely, but you can reduce it enough that the plants will still get enough CO2. This is why aquatic plants need good circulation, and higher CO2 levels than their terrestrial counterparts.
 

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Discussion Starter · #6 ·
Dissolved CO2 travels very slowly through water on its own. Only 0.0016mm per second!

And water in direct contact with leaves also moves far slower than free-flowing water in open areas of your tank; not only does the leaf block circulation, but the water itself behaves almost as if it was sticky.

So if you could actually see CO2 distribution in your tank, you'd see a thin layer on each leaf, about 1-2mm, where CO2 is much lower. The plant is consuming it faster than it can be replaced by either diffusion or water movement. This is known as the Prandtl Boundary.

You cannot eliminate the boundary completely, but you can reduce it enough that the plants will still get enough CO2. This is why aquatic plants need good circulation, and higher CO2 levels than their terrestrial counterparts.
THAT is an awesome explanation, I love to learn new stuff!! Well I picked up a new filter while I was out and put my diffusor as close to the bottom of the tank as I could, and it's also underneath the spraybar. So should I leave the diffusor towards the bottom as it is, or move it upwards toward the spray bar?


I'm also guessing that I'll need to up my bps then, I've only got 1bps at the mom. Plus this is a great time to experiment b/c I have no fishies in the tank yet.
 
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