# 2x external filter and C02 setup



## Paul195 (23 Mar 2016)

Hi 

This is also relevant to the filtration sub-forum.

I am starting a new tank which will be running two identical external EX1200 canister filters and a FE C02 setup with either one or two inline diffusers. I will be using an inline heater and either one or two spray bars for the outflow.

I need some advice on the best way to configure the hardware. Which of the following setups would you recommend and why ? 




 

Or is there a better way?? perhaps using a series or parallel configuration ? 
..Or maybe any of these are acceptable ?

Cheers
Paul


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## Martin in Holland (24 Mar 2016)

I would go for 6, but the spray bar sealed in the middle so each filter uses only half of the spray bar. With the diffuser placement this way you will get some tiny bubbles which are beneficial to plants as they can get the CO2 direct from the bubblus when they get stuck on the leaves and it safes you from a filter burp every now and then.


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## Chris Jackson (24 Mar 2016)

My vote would be for 4 but also as Martin said with the bar sealed in the middle (or two shorter bars, a long bar on each filter won't give you enough water output pressure from the bars). I don't like the look of CO2 micro bubbles in a tank at all so with the diffusers set on the inflows your filters are doubling as CO2 reactors which will give you really efficient usage with less CO2 mist. Plants will grow fine without mist.


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## ian_m (24 Mar 2016)

2, 4, 6 are dangerous. You must never ever ever ever connect two filter outputs (or inputs) together. If one filter fails, blocks, flow reduces or you simply turn it off, the working filter will force water backward through other filter, promptly emptying its gunky contents into your tank, most likely killing all the fish.

Also 1, 2, 3 are not recommended as the flow from both full width spray bars won't be very much. You are much better to make each filter do 1/2 the width of the tank, as in my diagram below.


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## Paul195 (24 Mar 2016)

Thanks a lot for your input chaps. Ian, what are the units between the non return valves and the diffusers in your diagram ?

I also noticed you are using a needle valve for each diffuser, is this necessary on a setup such as this? Only that I have bought a regulator which has a single needle valve on it.

If I have a spray bar for each side of the tank, any opinions on how to aim the jets to achieve surface movement, good circulation and C02 distribution?

Cheers
Paul


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## ian_m (24 Mar 2016)

Paul195 said:


> Ian, what are the units between the non return valves and the diffusers in your diagram ?


Two bubble counters so you can get CO2 the same for each diffuser.



Paul195 said:


> I also noticed you are using a needle valve for each diffuser, is this necessary on a setup such as this?


Yes this is absolutely necessary. If you use just one needle valve the CO2 will take the path of least resistance, usually cleanest diffuser, and you will get no flow from the other diffuser.

Oh, also make sure all the CO2 pipework is identical length so that it pressurises and depressurises at same rate.


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## ian_m (24 Mar 2016)

Paul195 said:


> If I have a spray bar for each side of the tank, any opinions on how to aim the jets to achieve surface movement, good circulation and C02 distribution?


This is the fine art of CO2 distribution, only when you experiment will you find out. I find the just changing the angle of my spray bar very slightly changes a nice drop green drop checker to yellow drop checker. This is angling it down, reducing surface agitation. Angling it up and increasing surface agitation results in drop checker remains blue.

Spray bar pointing down. Whoops.


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## Paul195 (24 Mar 2016)

Will it make a lot of difference in C02 distribution by injecting the C02 into both filters using the dual setup that you have suggested rather than just injecting it on one filter like in 1 above ?


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## ian_m (24 Mar 2016)

Paul195 said:


> Will it make a lot of difference in C02 distribution by injecting the C02 into both filters using the dual setup that you have suggested rather than just injecting it on one filter like in 1 above ?


Yes it will. You will struggle to get decent CO2 levels on the side without injection. Some people have managed to get decent CO2 with two spray bars across the back of the tank, but they had one small CO2 spray bar and a monster flow spraybar, usually from an FX5 filter. Unfortunately if you want optimum CO2 levels and optimum CO2 flow you will need CO2 injection in both spraybars.


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## spyder (24 Mar 2016)

I've thought about this in the past and would switch output sides so if the left filter is running co2 then take the outflow from the left and return on the right. Same with heating side on the right, outflow from right and return on the left.

That way heated and co2 enriched water should mix and swirl through each others filter more effectively, well it does in my head.

Putting co2 through 2 diffusers from one reg could be tricky balancing the outputs.


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## Paul195 (24 Mar 2016)

So to achieve this, would I just use a Y fitting to split the main pipe from the FE, open the needle on my regulator to fully open and then buy 2 new separate needle valves and bubble counters plus an extra diffuser.


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## ian_m (24 Mar 2016)

spyder said:


> ting co2 through 2 diffusers from one reg could be tricky balancing the outputs


Trivial with two needle valves and decent regulator, as explain by Paul195 above.


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## AndyMcD (25 Mar 2016)

Hi, this isn't recommended, but my set up is closest to 2, with two half tank width spray bars(split). 

CO2 is on the right, where plant density is highest and the plants are medium or advanced. 

The inline heater is on left where there are fewer plants and they're easy plants. 

My point is, even though the distribution isn't ideal, I'm hoping it will match the non-uniform demand. 

Andy


Sent from my iPhone using Tapatalk


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