River tank manifold problems.

[StraightClownin]

I'm having problems with my river tank setup. It seems that the current goes half way accross the tank, and then it whirls around and goes back to the powerhead side.

It's like the current makes a U turn.

The specifics.
tank: 6Lx2Wx18"H
1" pvc manifold.

5 outlets for powerheads.
3 inlets with giant sponges.

powerheads 4 maxijet 1200s
1 koralia 3 powerhead.
1 outlet is open at the moment.

Also on the same side of the tank, there is an aquaclear 110 to aid the current. The intake for it, is just normal, not built into the manifold.

1 foot in, from the left side(the side with all the powerheads/ac 110. Is the return spraybar from my eheim 2026. Also aiding the current.

I also have another eheim 2026 that I'm going to install on the tank. I also have another 2 aquaclear 110s that I can put on.

Basically I'm looking for opnions/setups from other people's river tanks? I've read martin's article several times. He even mentions getting stronger powerheads.

The powerheads i currently have seem weak. However, i suspect that the intake of the ac 110, and koralia pump and 1 output of the manifold that doesnt have a powerhead installed yet.


I think i may try to connect the ac 110 to the 1 output still available.

I'll take some pics and post them soon. gonna find a light, since mine are still being built.

left side/outputs


right side, intakes.

[chefkeith]

It just sounds like to me you have multiple vortex's in the tank.
When water enters the pipes, it creates a funnel shaped water motion. It's a 3D motion, like a tornado, hurricane, or how water goes down the drain.

Kind of like this-



The Koralia pump will create a small vortex also.

I'd experiment with the Koralia pumps position. Put it about 1cm below the water's surface on the opposite end of the tank. It might help change the water flow some. At the least it will agitate the surface and keep surface scum from building up. You'll be able to see the vortex it creates and might even hear it suck up water if it's too close to the surface.

[StraightClownin]

Now that is something I hadn't thought of. Two different vortexes. One from the powerheads, and one from the sucking of the manifold.


I wonder if i can fight this. ie, putting my return spray bars towards the middle. or if it's a lost cause. Ie, i'd need too much pressure from the powerhead side, and would crash into the other side of the glass.. thus causing flowback anyways.

[Bully]

I would also experiment with the Koralia. My Koralia 2 is positioned 12" from the surface and if I turn my externals off so it's the only pump running, it still creates a vortex that is visible at the surface. Also you don't have the flow nozzle fitted to it, this means that you are creating a multi-directional current in the tank that's certain to disrupt the flow from the powerheads. Have you tried turning the Koralia off or using it with the flow nozzle to see if it makes a difference?

[StraightClownin]

I actually need to locate the flow nozzle. I have moved it a few times, and turned it off. The return pressure seemed stronger without the koralia. So it seems at the moment it's doing more good than bad.

[StraightClownin]

i found my flow nozzle. It does make a difference in the flow of it. I think the culprit is the ac 110. it's providing alot of current at the top of the water. however, it is going through the middle of the top, and when it gets weaker, creates a U turn on the current. I suspect if I had another koralia pump, placed at the top of the water column, with the ac 110, it wouldnt create that current.

[Sea Sprite]

I would be no help in advising you...
Mine is up & running with good current, but then my tank is only a 4' x 18" and about 20" high, 75g. For output on the manifold I'm using an aqua clear 50 & a penguin 1140. Then suction cupped to the back wall I have a maxi-jet 1200-with an attachment added (I put the larger impeller on)...and then the fluval XF5 .
Of course these are all pushing water from the same end.
Intakes on the manifold are 2 large pond filter sponges and the FX5.

Good luck, I'm sure you'll get it working well.

[Diana]

Even in a river there will be multiple currents going on, in addition to the main current.

Are the fish happy?
Is the tank staying clean? (Surface scum, and bottom debris)
Are there some relatively calm places where the fish can get out of the water flow if they want?
Is the food well distributed so all the fish get a chance without one fish hording it all?
Does the tank overall look nice? Plants waving in the current, not blown over like in a hurricane? Fish scattered here and there according to their preferences, utilizing the whole tank?

I do understand the basic idea is that there is one main flow that is pretty intense, but a river tank does not have to be a solid wall of water racing from one end to the other.

[StraightClownin]

Even in a river there will be multiple currents going on, in addition to the main current.

Are the fish happy?
Is the tank staying clean? (Surface scum, and bottom debris)
Are there some relatively calm places where the fish can get out of the water flow if they want?
Is the food well distributed so all the fish get a chance without one fish hording it all?
Does the tank overall look nice? Plants waving in the current, not blown over like in a hurricane? Fish scattered here and there according to their preferences, utilizing the whole tank?

I do understand the basic idea is that there is one main flow that is pretty intense, but a river tank does not have to be a solid wall of water racing from one end to the other.

These are good points, perhaps I'm getting too wrapped up in the "idea".

I havent yet put any fish in it. Due to me wanting to finish all the tinkering

[Tinman]

You may truly visulize your current by crushing flake food and adding it to your tank.
You do not want separate areas of flow .The tank should mix nicely in it's entirety. Point the nozzles off to the same side so they work help each other to swirl your entire tank.
The lowest pressure spot will collect the trash so............ Put all the pumps working the same way at the same end spraying on the front slightly to attract the fish to the front............and then your cannister at the other end to collect trash at the slow end and then put the spray rail spraying back towards your intakes again at the far end blasting the surface...

I had issues with massive flows in vortexes leaving absolute dead spots at the bottom that would not let the water in some areas of my tanks get to my filters.It proved deadly as the fish in the calm spot were also in their waste.

Use all your pumps pointing at one far corner... IMHO

[Diana]

Also, with no fish in the tank yet you can use food coloring to see how the water moves. In that large a tank you might go through quite a bit, though!