# Large scale river manifold set-up



## Ted (7 Mar 2016)

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.


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## ian_m (7 Mar 2016)

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.


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## Paulo Soares (7 Mar 2016)

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.


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## dw1305 (7 Mar 2016)

Hi all, 





ian_m said:


> 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


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## BruceF (7 Mar 2016)

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


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## Chris Jackson (7 Mar 2016)

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.


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## Ted (7 Mar 2016)

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!


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## Chris Jackson (7 Mar 2016)

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


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## AndyMcD (8 Mar 2016)

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


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## dw1305 (9 Mar 2016)

Hi all,





Chris Jackson said:


> 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


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## Chris Jackson (9 Mar 2016)

dw1305 said:


> 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.


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## zozo (10 Mar 2016)

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..


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## BruceF (10 Mar 2016)

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


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## zozo (10 Mar 2016)

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


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## AndyMcD (11 Mar 2016)

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.


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## zozo (11 Mar 2016)

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


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## AndyMcD (11 Mar 2016)

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.


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## AndyMcD (11 Mar 2016)

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


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## Ted (2 Jun 2016)

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.


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## dw1305 (3 Jun 2016)

Hi all,
The tank looks really good. 





Ted said:


> 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


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## ShawnMac (3 Jun 2016)

I have built one of these before. Worked very well to generate laminar flow. It doesn't act as filtration of course. It would take some creative hardscaping to hide it though.


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## AndyMcD (4 Jun 2016)

Building on what Darrel and Shawnmac have said, I'm sure you'll have read the following, but if not, you may find these very interesting:

http://www.loaches.com/articles/a-river-runs-through-it

http://www.loaches.com/articles/hillstream-loaches-the-specialists-at-life-in-the-fast-lane

http://www.loaches.com/articles/river-tank-manifold-design


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## Ted (5 Jun 2016)

Interesting Daniel - I didn't realize the extent of CO2 risk posed to the gobies. The biology makes sense. That said, I suspect the presence of CO2 isn't binary. With a controller, I can maintain a PH of 7.5, which given my hardness, wouldn't interfere with their respiration. I'm definitely not going to pump any more than that. 

In terms of ferts, Rachel O'Leary doesn't dose her manifold set up at all, presumably to keep TDS at levels it would be found in nature. I've been trying root tabs for the crypts but not having much luck. Any thoughts there?

@AndyMcD great links - very interesting. Thanks.


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## dw1305 (5 Jun 2016)

Hi all,





Ted said:


> With a controller, I can maintain a PH of 7.5, which given my hardness, wouldn't interfere with their respiration. I'm definitely not going to pump any more than that.


It should be all right, but I'd keep a close eye on the water temperature, as it rises you can still have problems with <"low dissolved oxygen levels">, due to reduced gas solubility with rising temperature.





Ted said:


> In terms of ferts, Rachel O'Leary doesn't dose her manifold set up at all, presumably to keep TDS at levels it would be found in nature. I've been trying root tabs for the crypts but not having much luck. Any thoughts there?


If you aren't dosing fertiliser, your plants are unlikely to be CO2 limited (it is back to <"Liebig's law of the minimum">).

If you have water high in carbonates (as HCO3- and their related cation, usually Ca++), the pH will be stable at pH7.8, and the conductivity will naturally sit at ~600 microS. As you add chemical salts conductivity will rise, but for fish from limestone rivers that isn't a problem. 

If I wanted to grow green algae I'd definitely:

 have alkaline water, 
dose some fertiliser (green algae belong to the <"same clade"> as all the higher plants), 
I'd go for a long light period (at least 12 hours).
I'd have a low plant mass.
In terms of fish health I'd change enough water to reset the tank conductivity level to the background level every week. Have a look at Jordi's post <"here">.

cheers Darrel


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## Ted (16 Mar 2017)

Hi all - wanted to provide an update on this tank and ask for a spot more of advice. I've taken on much of your awesome advice and am loving the tank. The aufwuchs growth is awesome and the fish (stiphodons, sewellia, garra flavatra etc) are thriving.

The only issue is that the green algae accumulating on the glass is driving me nuts. It's absolutely CAKED on and requires a good 2 hrs to scrape off each week, which has sadly led to me scratching the heck out of the acrylic (see the photo). You can see that my algae eaters are 'helping' by nibbling the algae off the glass but aren't really making a dent.

Question for you guys:
1) Do you think I should dose less / reduce light period or intensity / or try incrementally higher levels of Co2 injection?
2) Is there a specific chemical imbalance that could be causing this type of algal accumulation or is this just the price you pay for having a plentiful source of aufwuchs.

Details in case helpful
+ Alkaline water kept at 24C
+ 2 Fluval FX6 and a massive koralia so LOTS of flow
+ Dosing EI (and Excel)
+ Lighting: 6x80w T5 with 10 hour photoperiod
+ 50% water change per week
+ Injected Co2 to bring pH to 7.1 (vs 7.8 tap water)

Thanks!


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## zozo (16 Mar 2017)

In my low tech experience, i have lights on from 8 am to 8 pm within the compansation point of the plants. 5 hours more light bellow that compansation point. And so i ramp up my lights slowly as nature would do, go up in steps from 0 at  8am to noon, have the highest intensity from noon to 5 pm and ramp it down on steps again to 10% at 8 pm. Keep the 10% on till 11 pm then it goes 0 again.

It works like a charm still not at a full 100% in the high periode with 60 watt's of led lights total at full power.. That's trail and error to find out.. But found the sweetspot not to have to much algae growing on the glass. What grows on it is easily wiped off with a sponge during the weekly water change. I have algae or aufwuchs growing on the rocks.. Wood and plants are relatively clean.

I dose my tank with potassium nitrate, potassium phosphate, magnesium nitrate and traces. 

Tho i have a bit more plantmass then you have.. But my guess is, definitively intensity is playing the biggest part not the periode. 

That's the nice thing about leds, it is easily and cheaply automated when it comes to dimming options.. Anyway, seeing your plantmass than 6x 80 watt is a tad much. Since you have a pendant light what you could try is play with the height to reduce light in the tank.. Double the height and see how it goes and go back down if needed..

High tech i have the same experience, it has 12 hours and a tad higher intensity mid day periode and about the same schedule.. Also a pendant hanging 40 cm above the tank.. Funny is almost everybody yells, low co2 is the cause for algae to thrive.. I have less algae in my low tech.. 

Many forget..


dw1305 said:


> dose some fertiliser (green algae belong to the <"same clade"> as all the higher plants)


So it also likes co2 as much as the plants do as well as light.


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## AndyMcD (16 Mar 2017)

Have you considered moving your light back or lower or angling it or taking a tube out so there is less light on the front glass?

A black background may mean algae is less obvious, on the back surface.

The aquarium looks great! I'd love to try this style of tank.


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## BruceF (17 Mar 2017)

More phosphate!


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## Ted (17 Mar 2017)

Thanks guys! 
I'll try:
1) Raising the lamp a few feet
2) Removing front and back bulbs
3) Increasing phosphate

I'll try them independently so that we can see which does the trick. Fingers crossed.


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## Ted (16 May 2017)

Hi - thanks again for offering up some suggestions to reduce algae on the glass. I tried each independently - the winner was #2 (removing front and back bulbs).

Here were the results:
1) Raising the lamp hampered plant growth in the depths of the tank and led to a cyanobacteria bloom in places with poor circulation (behind the poret-foam corner filter intake)
2) Removing the front and back bulbs while keeping close to the surface reduced algae on the glass by about 90% and the plants are doing great
3) Increasing phosphates didn't make a noticeable difference 

Appreciate it. I'll post photos once the plants make a bit of a comeback. I also read that there's a way to remove scratches on acrylic, which sounds like a pain but will be worth it.


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