River Flow Rate?

[Noto]

Do you already have the tank? If not, consider getting/building:

(a) a really long, narrow tank (to decrease the backflow and eddying inherent in any stream-in-a-box)

(b) a racetrack-style tank with a central divider, allowing linear flow to go one way along one side of the divider and the other way on the other side

I have set up stream tanks (55 and 75 gallons) using both the "loach manifold" design and a canister filter with intake and return at opposite ends of the tank. There is still a great deal of turbulence in both designs. The fish don't seem to mind terribly, but if you want a more linear flow you will need to use a more extreme design.

Here's a stream tank design I've been considering:

The idea is that the sloped substrate will prevent the massive eddies and backcurrents that occur when the water hits the endwalls. Of course, a lot of tank space is lost as well.

 

[Fishman0]

Your idea is very good, i agree that it would use alot of tank space tho

a while ago i considered building a tank with one large/many suction lines on one side and a few returns plumbed into the wall on the other. this would prevent just circulating the water within the tank. Then after considering that there are already built, and fairly cheep tanks out there, i wanted to see if i could make something else work.

I may go with a 55 but i am not sure yet

 

[Jgray152]

again i was just wondering what recomended flow velocity i should build to.

thanks for all the input

Well you should figure out how much flow volume you want first and then design it to increase the velocity.

No one will be able to tell you how many inches/feet per second you should shoot for so I still think you might be thinking to hard. Just find the flow you want, say 1200 GPH and then get your velocity where you want it. Between the pitch of the river and the width of the river you should be able to get the velocity where you want it.

 

[xdragonxb0i]

just shoot for a 5x or more turnover rate, with a spray that can produce a current on one side of the tank. Anything over 5x will produce a fairly good current

 

[mfgl]

Best I can do is this...I just did a little experiment.

It takes between .79 and 1.1 seconds for it to push a piece of flake food across the tank when dropped directly into the flow. Will round this off to 1 second. tank is 4ft, I dropped the food in about 6 inches from one side so 60x3.5 240ft per minute.

About the same speed of the water I trout fish in Central PA.

It doesnt really make a whirlpool. it hits the other side of the tank and rolls under then there is current going back the other way across the gravel. It keeps my substrate really really clean. I assume its not overstressing my fish since he rarely ever hangs out in the safe area unless he is hiding.