Co2 though one or two external filters?

[UllavL]

Hi,
I'm buying my first Co2-system and since it's my first I find everything rather complicated Therefore I'm leaning towards a complete system that an expert already have put together like this one with an atomizer diffusor.

Now to my question. My tank (journal here) is shallow and long measuring 120 x 32 x 22 cm. I'll be using two external filters (Eheim pro 3 350 and 350T). I thought I'd just push the C02 through one of the of the outflow hoses/lily pipes. Is this a stupid idea? Should I get two atomizers to put on each outflow hose? (considering C02 distribution) I really don't want to do that because then I have no idea what I should buy. But on the other hand: it's too much money to spend on something that won't work properly.

Would be so kind if anyone had the time to advice
Ulla

 

[Jose]

One atomizer should be enough, as long as the flows from the filters dont break each other. Basically youll have to put both outlets on the same side of the tank and flowing in the same direction.

 

[flygja]

Having two atomisers is also a hit-and-miss for me. I bought two same brand same model atomisers and CO2 just refused to flow through one of them when both are placed in a splitter.

 

[UllavL]

Great! Just what I wanted to here thank you so much @Jose and @flygja!

 

[ian_m]

You need to split CO2 like this.

 

[UllavL]

You need to split CO2 like this.

Do I need to or is ut just the optimal way and the other method almost as good? I wan't be using spraybars and the hardscape will make it impossible to place them like that. Thanks Ian for posting the picture!


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[ian_m]

If you are using two filters your really should have two CO2 injectors or else you will have CO2 issues. Spray bars or lily pipes, doesn't matter as long as there is decent flow of CO2 saturated water all over the tank.

You must split the CO2 after the regulator and have separate needle valves to get individual CO2 rate control. If you feed regulator -> single needle valve to CO2 splitter -> two diffusers, the CO2 will take the path of least resistance and you will end up with all the CO2 going in via once diffuser.

 

[UllavL]

Thank you so much for explaining @ian_m
Could I just check with you what I should buy then? If I order this system and add:

• 1 2-way splitter
• 2 needle valves
  
• 1 bubble counter
• 1 atomizer diffuser

Or am I getting it all wrong?
Thanks,
Ulla