Loaches Online Forum

I know this has been discussed in a previous thread. I recall seeing it. I just can not for the life of me find it right now.

My question is about the flow in the river tank I just set up. I used Martin's article as a blue print and my specifics are: 75 Gallon tank with 2 Aquaclear 70s on the manifold. Output from 2 eheim eccos on the powerhead side of the tank as well.

The flow along the bottom of the tank is excellent.

However it seems to be creating a vertical circular flow. Would be easier to draw, but here is the best way I can describe it:

Along the bottom of the tank there is good flow from powerhead to intake. Along the top of the tank there is strong flow from intake to powerhead. Creates a looping circular action.

Was just wondering if this is normal or if I need to tweak some of the components to tame it.

EDIT: I forgot to add that I placed the powerheads fairly low in the tank. Close to the substrate. Thinking that loaches liked the bottom more and it might give the dither fish a break up top. Was wondering if that is contributing to this.

I found the thread/post that talked about this.

It was from Keith, and here it is: http://forums.loaches.com/viewtopic.php?p=53848#53848

Looks like he decided to tackle the flow in a different way, sans manifold.

Normal.

Martin.

Great. Thanks Martin.

I can stop obsessing about it now.

You will likely never get a 'perfect' flow pattern, so read the fish. Are they happy with the set up? Are they moving throughout the tank in the areas they prefer?

Diana wrote:You will likely never get a 'perfect' flow pattern, so read the fish. Are they happy with the set up? Are they moving throughout the tank in the areas they prefer?

Unfortunately, the powerheads seem to be clearing out the middle of the tank. Even with just 1 of them running it is sending all of the fish, loaches and dither, running for cover. Usually huddled behind the powerheads, behind the intake sponges, or in one of the corners.

It is possible the flow is just too strong for their size. Or maybe they just need to get used to it?

Either could be the answer, but I would redirect the power head or use a smaller one. Is it possible to fan out the output from your PH?

I aimed one PH at the front glass. The direct flow was too much, but the deflected flow was perfect: The Clown Loaches surf it often!

In my river tank I have the PH aimed about through the middle of the tank and most of these fish are bottom dwellers anyway, but the few mid-stream fish I have in there stay out of the direct blast.

Aquaclear 70's can adjust the amount of flow, can you turn the flow down anymore or is it already down all the way?

Thanks for the tips.

I re-added the yellow flow plate back into the AC 70's to try to cut back on the power, but it was still too much.

There seems to be another way to further decrease the power, but it would involve reversing the flow. By that I mean, there is a way to set the AC's so that the main spout will suck in water, instead of blow out water. Which also means that the hole in the bottom of the powerhead which usually sucks in water, will instead blow out water.

There is a lever that lets you do this. As you move that lever and approach the middle setting the out flow from the main spout begins to decrease (as it gets ready to suck inward instead). Which is good. But I can't tell if at the same time it does this if it is creating some blow out the bottom. Which would be bad since that would mess with the whole concept of the manifold intake on the other end.

I think I found a balance that I am comfortable with right now. And more importantly, the fish seem comfortable with.

I pointed one of the AC70s diagonal across the tank, and through the driftwood, to try to disperse its flow a little. I replaced the other 70 with an AC30 I had sitting around and that is the powerhead that blows down the middle front of the tank.

I also pointed the return from my two eheim filters into the glass. I am still getting good splash/aeration but the current on the top is reduced which has had the effect of bringing out the smaller dither fish from their cover.

Hard to say how much the loaches are enjoying it as they are really yet to venture out too much. Lots of nervous energy with them right now. I think the new tank, and 2 new buddies have them pre-occupied.

Here is a video of the new setup: http://www.youtube.com/watch?v=znKFBz-tqMI

Looking forward to getting my shipment of plants!

Sure looks like the fish are having fun in there!

Your tank looks good. Your analysis of the flow is the same as I deduced. I think that what works best is highly dependent on what decoration obstacles are in the tank. No matter what you do, there are going to be eddies and unexpected currents. That is not a bad thing. I only chose to do a horizontal circular flow since I have a lot of wood in the center of the tank for the flow to go around. Your loaches are going to like the currents. Changing it up periodically (by redirecting it a bit) helps keep the loaches interested and active. When I change mine even a little bit, they come out and play in it, and explore the new currents.