# Optimal CO2 Diffuser Placement in a 20 gallon long?



## hennyis1 (Oct 5, 2017)

Hello again fellow planted tank enthusiasts!

Just had a question regarding the placement of a CO2 diffuser. I have one of those small glass ceramic diffusers and I've been trying to figure out the best place to put it. At first I had it at the end that was opposite of the powerhead but very close to the water outflow from my canister filter. With it in this part of the tank I noticed a lot of tiny bubbles clinging all over the plants and stuff, even under the leaves of bigger plants (is this pearling?) and along the glass and substrate. 
A few days ago, I decided to move the diffuser around and placed it as close as I could under the intake filter of the powerhead. The sole purpose of the powerhead is to increase oxygenation and water agitation but since the diffuser's been there, I have noticed less tiny bubbles on the plants and stuff compared to being placed at the other end of the tank. 
So based on the lack of tiny bubbles clinging to the plants, does this mean the new placement is not as beneficial as the first? Is it due to too much water agitation?

As usual, any thoughts or suggestions are greatly appreciated.
Thank you!


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## Jeff5614 (Dec 29, 2005)

I would place it directly opposite of the outflow from your canister of power head, but your original placement sounds pretty good. If you're going to go with any sort of misting method having those tiny bubbles sprayed onto the leaves is what you want.


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## hennyis1 (Oct 5, 2017)

Jeff5614 said:


> I would place it directly opposite of the outflow from your canister of power head, but your original placement sounds pretty good. If you're going to go with any sort of misting method having those tiny bubbles sprayed onto the leaves is what you want.


Great -thanks for the reply! I think I will change it back to where it was originally too. 
I was looking at getting one of those inline infuser things but it seems a bit more complicated than I'd like to deal with.


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## houseofcards (Mar 21, 2009)

You could go either way. If the flow is strong enough then you could place it on the opposite end of the canister outflow. If not place it directly underneath it. co2 bubbles as clinging to the leaves as stated by @Jeff5614 is good. There are some that think this is even better than fully dissolved co2 via a reactor. 

BTW it's not pearling, pearling starts from within the plant as oxygen is released at such a quick pace it can't fully dissolve into the water.


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## Jeff5614 (Dec 29, 2005)

hennyis1 said:


> Great -thanks for the reply! I think I will change it back to where it was originally too.
> I was looking at getting one of those inline infuser things but it seems a bit more complicated than I'd like to deal with.


Inline is fine if you want it out of the tank. But there's something very Amano'esque to me when it comes to a glass diffuser in the tank. I occasionally put mine back in in an effort to pay a bit of homage to the master.


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## hennyis1 (Oct 5, 2017)

Thanks for the replies, everyone. The way my tank is set up, I have my spray bar on the back left (if standing in front of it and looking right at it). I really wanted to get the co2 diffuser under the spray bar, but the way my hardscape is set, it's kind of challenging to do that and the co2 tubing is really stiff so getting the diffuser to be straight in the tank is challenging too.

But I'm going to keep working at it and hope that the co2 is being properly dispensed in the tank.


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