Large scale river manifold set-up

[Ted]

Hi - I'd love some advice on how to pipe up my 150 gallon river manifold set-up. At a high-level, I'm planning to run two fluval fx6. A traditional manifold runs heavy flow in piping under the substrate. Instead, I'm rounding it behind the tank. Rachel O'Leary set up something similar (great videos if you're interested in this set-up, btw: )

Set-up
You have an intake behind a corner layer of Poret foam that runs through two fluval fx6. They then lead to a single spray bar at the opposite end of the tank.

My main questions are:
1) Can you combine the intake and outflow of 2x filters using a y-bend? Do you give up any flow-rate? Is there a better way of doing this?
2) Do you think a 1" PVC could take the flow of two fluval fx6?
3) Would a combined spray bar capture the same potential flow as 2x separate spray bars?
4) Do you envision any difficulties I missed in the diagram?

Many thanks guys - I'll be sure to post photos.

 

[ian_m]

You must never ever ever ever join the inputs and outputs of filters together.

There are a couple of issues.
1. If one filter stops/fails/blocks you can end up forcing water backwards through it. There have been people here who have wiped out their tanks, when one filter fails/blocked it ended up reverse flowing and emptying all the filter detritus into the tank, wiping everything out.
2. One filter will always be slightly more powerful than the other ie the less dirty one and this will reduce the flow of the other one by providing either outlet back pressure or suction on its inlet.

Both filters must have separate inlets and outlets.

 

[Paulo Soares]

And more..
Puting two filter working in serie will not improve any flow. You will have the same flow / powerhead of one single.

Best Regards.

 

[dw1305]

Hi all,

Both filters must have separate inlets and outlets.

I agree with this as well.

Where do you want the laminar flow? If you want it down by the substrate, you can just put the two spray bars on the end wall towards the bottom of the tank. Flow will then go one way along the bottom of the tank, up the far wall and back in the opposite direction along the surface.

You can still have the intake behind the <"Eck HMF"> in the far corner from the spray bar.

I've done this and it works really well.

cheers Darrel

 

[BruceF]

This is a good write up,
http://www.onsnatuurgenot.nl/aquarium/walstad.htm

 

[Chris Jackson]

I personally think that for a fast flowing river type of effect you are better off creating the flow with powerheads or Maxpect Gyre devices because you need a great deal of water movement to really achieve that effect. Let the filters work primary for filtration at lower flow rates.

Perhaps if you had foam/mesh baffles across the width of each end of the tank and had a big pump and the FX6's inflowing one end and outflowing the other then you could get a genuine full flow effect from one end to the other but you'd need a lot of pump power.

This is the effect I got with one Maxpect Gyre 35w in a 4x2x2 tank at a near silent half power15ms setting along with two 1000lhr rated filters. The flow is a circular but the effect is still similar to that of some eddy currents along the banks of a stream.

 

[Ted]

Thanks guys - this is exciting and great write-ups.
Here's what I'm planning now:
+ I'll connect the Fluvals as two separate spray bars and keep the systems discrete. Two fx6s should lend a lot of flow on their own.
+ I'll use a couple of very powerful Koralias I have on hand to get additional flow. Might as well
@ianM - you averted a disaster.

One last question - will I capture more directed flow if I use a pvc spraybar (with large diameter holes) or the fluval off-the shelf jet? Cheers!

 

[Chris Jackson]

I'd say more even with the spray bar and with large holes it won't restrict the flow as much as they normally would

 

[AndyMcD]

Take a look at this video. Puts 'high flow' into perspective!!!

 

[dw1305]

Hi all,

This is the effect I got with one Maxpect Gyre 35w in a 4x2x2 tank at a near silent half power15ms setting along with two 1000lhr rated filters. The flow is a circular but the effect is still similar to that of some eddy currents along the banks of a stream.

I think that is enough flow even for rheophilic of fish.

cheers Darrel

 

[Chris Jackson]

Hi all,I think that is enough flow even for rheophilic of fish.

cheers Darrel

Indeed, there are 3 Sewellia "spotted" Hillstream loaches in there that would certainly be classed as rheophilic and they seem very happy grazing on the rocks. The Maxpect is placed high enough that it creates a vortex from time to time that draws air into the water as well so plenty of O2 is added.

 

[zozo]

http://www.practicalfishkeeping.co.uk/content.php?sid=5455
The tanks shown in the link, is same setup as in link from BruceF.. I know there is an article or blog or tutorial or journal about seting up such a tank complete with photo's from start to end.. I'm not sure but thought i found it here at UKAPS and it's from a well known website with forum about anything aquarium. Could be the same website i posted in this answer.. Sorry i realy forgot, but it was very intresting article..

 

[BruceF]

He used to post on APC
http://www.aquaticplantcentral.com/forumapc/el-natural/84700-my-1-20cm-hopefully-npt.html

 

[zozo]

Ah here it is, i meant this one.. Found it not with Hillstream but River tank..
http://www.practicalfishkeeping.co.uk/content.php?sid=4922

 

[AndyMcD]

Thinking about this (while stuck in traffic yesterday), why a spray bar? Won't the flow from all the holes be more chaotic?

If you're looking for oxygenated, laminar flow, have you considered one duck bill and one Venturi fitting?

Duck bills would give you a more laminar, jet like, directed flow, but won't increase oxygenation unless placed at the surface.

A Venturi fitting would give a similar flow, but would add oxygenation (bubbles to break surface).

You could then bump up the flow with additional power head.

This is a lottery winning biotope I'd love to do! If it was me, I'd like a long, narrow, shallow tank with filter outlets and power heads at one end, hidden behind rocks or in caves (as if you've come off a waterfall or riffle - emersed plants?). I'd be tempted to do an S shaped formation of rocks, to allow areas of respite. I think filters instead of a manifold is a good idea.

 

[zozo]

+1 for AndyMcD duckbill works very nice, using one in my latest setup.. If something mimics a river stream its a duckbill..

 

[AndyMcD]

What about something like this?

A couple of local fish stores have had the filter outlet above the water, flowing in off a rock.

With slate, it may be possible to build a waterfall to hide the equipment.

You could possibly have plants in the corners, but keeping soil separate may be a challenge.

 

[AndyMcD]

Instead of slate, you could perhaps use walls and rocks like these to create a structure:



http://aqua-maniac.com/eng_m_3D-Backgrounds_Grey-Thin-Rock-Backgrounds-157.html

http://aqua-maniac.com/product-eng-165-Bundle-of-5-grey-aquarium-rock-.html

 

[Ted]

Hi all - I wanted to post a work in progress on my manifold 150 gallon. I'm loving this tank so far. Thanks for your wisdom and suggestions.

So far I have the two Fluval FX6s plumbed in and some supplemental filtration. I had previously used two stacked spraybars, which created bad turbulence that messed with the fish as you suggested @AndyMcD. They're much more active with the single spray bar creating surface agitation and the corner jet,/duck bill which provides some additional flow.

I just added a CO2 system today to get some better plant growth and fend off some bad algae. My stiphodon gobies need aufwuchs (the green algae on the rocks) to thrive - I'm hoping that the CO2 doesn't mess with its formation. I don't want to think about how quickly I'll be burning through my 10 gallon canister given the amount of surface agitation...

The next step is to add some koralias as posts above suggested. I'm thinking about two mammoths behind the rocks at the left hand side. I suspect this will cause a significant eddy around the rocks, but that may not be a bad thing.

I'll keep you posted. Thanks again all.

 

[dw1305]

Hi all,
The tank looks really good.

I just added a CO2 system today to get some better plant growth and fend off some bad algae.

It won't be lack of CO2 that is limiting your plant growth, because it is a shallow tank, with lots of flow, CO2 levels will never become very depleted, mainly because of the large large gas exchange surface.

You could try adding a bit more fertiliser, <"green algae need the same conditions that higher plants need">.

The real problem for me would be that injecting CO2 also adds the very real risk of gassing your fish. Rheophilic fish don't have any physiological adaptations to high CO2 levels, and can be asphyxiated via the <"Bohr Root effect"> even if dissolved oxygen levels are high.

cheers Darrel