# Connecting 2 Eheim 2080/2180, sharing pipes



## Cayambe (28 Jul 2017)

I use an Eheim 2180 (2 intakes, 1 outflow) for my 850L tank. I'm considering adding another Eheim 2080. 

The 2180 is currently connected to 3 pipes feeding directly into the tank from beneath (2 intakes, 1 outflow). This is all good.

Now, I want to connect both pumps to these 3 pipes. And am wondering if there would be any benefit at all, or if the sharing of the pipes would cancel out the benefit?

Goal is to get more outflow and better filtration. Could it work?

See the drawing. I also added a picture of the pipework.


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## Zeus. (29 Jul 2017)

Think the increase in flow would be minimal as the water flow will be restricted by the diameter and length of the pipes they share. You would need to increase the diameter of the pipes they share, plus inlets and outlets to see any real gains in flow. They would be some increase how much dunno. As to the filtration you would obviously have a nearly double increase in the filtration surface area, but unless your planning adding more livestock and your present filter is coping why add another as it would be wasted. Your present filter might not be at its biological filtration capacity yet anyway.

If you want better filtration get better media esp biological ceramic media, that would increase the biological filtration capacity of your present filter which once cycled will kick in as it needs it. Depends on what media you presently have.
Better flow - what return fitting are you using ? lily pipes/spray Bar. I use a spray bar and I took it off to see how the flow was and just used two 25mm pipes. The filter turn over rate would have gone up but the flow was pants, the plants handy moved. Put spary bay back on and flow in tank is fantastic, but the filter turnover is less as more resistance.

Little Videos I did to try and show the flow in Tank with aid of Twinstar.

First video is with the Fluval FX6 only on.



Part two is with the Fluval FX6 and Eheim 3000+ on



If after better flow why not just add powerhead/wav maker


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## Cayambe (29 Jul 2017)

You have some valid points. Further reading proves your points further. The pipes will be the determining factor, limiting/allowing flow. Even though ill get more filter volume, ill probably not get much more flow. 

My return fitting is an inverse L shape pipe with a 22mm opening. I could perhaps increase the flow with a spray. But I need more flow nonetheless.

I'm thinking about adding that new Akamai kps or one of those Jebao/Jecod RW-15. The Akamai might be too little for my 850 liters to move around. These Jecods looks very powerful.


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## Cayambe (29 Jul 2017)

That's a very nice looking tank you got there btw.


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## Zeus. (29 Jul 2017)

Cayambe said:


> But I need more flow nonetheless



What kind off flow? 
I ask as its relevant we use use the term FLOW to cover many things. The general rule of x10 filter turnover per tank size is based on estimates of what works in general. My Fluval FX6 has a turnover with standard media of 3500L/h my tank is 500L so it falls short a long way when the Fluval is only on so hence the independant line. This was my first planted tank high tech so I wanted to make sure I had enough 'FLOW'. The vid show the tank flow is great even with just to Fluval on as its the spray bar moving the body of water. may spray bar has twenty five 4mm holes and two 3.5mm holes in it which 'push' the water round the tank keeping the CO2 and ferts mixed up and hopefully no/few dead spots. But the spray bar reduces the filter flow as the twenty five 4mm holes and two 3.5mm holes create more resistance than one or two large openings.

Here




so at best the fluval turnover is 29% short of the X10 rule I think its more like 40-50% short - yet since posting the vids I have many comments on how good the flow is and no dead spots, even had some says the flow is more like a reef tank.

So maybe a custom spray bar and maybe some better Ceramic media would be a better easier way of upgrading your filtration system. I dont use the fluval ceramic media, dumped it straight away for stuff with higher surface area to volume ratio.



Cayambe said:


> That's a very nice looking tank you got there btw.



Thank You , to kind


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## geoffbark (1 Aug 2017)

You will see a flow rate increase by running two pumps in parallel with the same head, although in theory the flow rate should be doubled, in practice it is more like 1.5x. It is also common to use identical pumps.


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## zozo (5 Aug 2017)

2 filters sharing the same inlet could work very well if sized correctly.. But why not use 2 outlets, 1 for each filter? This only will benefit the flow in the tank and the filters never ever wont restrict  one another..


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## Andy Thurston (5 Aug 2017)

Problems with 2 filters sharing pipework is that problems can occur with filters overpowering each other which can potentially result in flow moving the wrong way through the pipe work and flow from one filter cancelling the other filter or even one filter pushing water the wrong way  through the other resulting in dirt being pushed back into the tank


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## Cayambe (27 Jun 2018)

zozo said:


> 2 filters sharing the same inlet could work very well if sized correctly.. But why not use 2 outlets, 1 for each filter? This only will benefit the flow in the tank and the filters never ever wont restrict  one another..



Aaaaand I'm back..

The reason why I can't use two outlets is because of the hard plumping of the tank. I have 3 pipes going in from the bottom. So I can't get more pipework, unless I have to run the pipes on the outside of the tank, which I won't do. I never came around to fitting another canister to the setup. I did add some prefilters to the intake pipes which has helped.

It all works alright. I still would like to either get a sump/another filter going, to get more mechanical filtration.

Right now the 3 trays in my eheim 2180 is filled with biohome ultra. Maybe I should empty the bottom tray, and add foam/mechanical. 

Right now I have decided that another tray with biomedia is more important..

Its a hard compromise, so I keep turning back to the thought of adding another filter to the same pipes, to get more volume.

A normal person would probably just add a sump.


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