creating random flow vs heavy flow

[96p993]

I understand random flow and its advantages (ie waves) but Im under the impression if you have 2 powerheads on the back/side glass pointing at each other in the middle of the tank this "crashing" will cause all kinds of randomness throughout the tank...both heavy and soft flow in different places in the tank.

Now we have the same 2 on and Apex ranging flow from 0 to 100%...This also creates random flow but making the flow soft or hard on its way to the middle of the tank.

Im just not sure I see the advantage to one over the other....What I do know is adjustable flow powerheads demand a much greater price then constant flow.

 

[Bd670]

ill be following along ... great question

 

[Ben_1313]

Well mostly because patterns are predictable even with constant flow pumps pointed at each other. So if you have two pumps facing each other while going at random speeds it's completely unpredictable.

As for the price, it's probably because controllable pumps are at the top end of the market thus demanding a greater asking price. That and you have to figure in the cost of development/parts/labor of including a controller with it.

 

[96p993]

Have you seen any studies that show the flow is predictable? Im just not sure I buy that one, with all the items in our tank (rocks, walls, sand, etc) I just dont see flow becoming predictable...I would be shocked if someone hasnt done flow studies, just not sure if they revolved around aquariums...

As for price, I didnt really bring that up as to start a debate on expensive vs cheap. I run all Tuzne pumps and believe that are worth the expense.

 

[FlyPenFly]

It's a magnitude question. Sure constant flow pumps can have a small amount of randomness but pumps with random modes are far more chaotic than constant flow pumps.

 

[Ben_1313]

Have you seen any studies that show the flow is predictable? Im just not sure I buy that one, with all the items in our tank (rocks, walls, sand, etc) I just dont see flow becoming predictable...I would be shocked if someone hasnt done flow studies, just not sure if they revolved around aquariums...

As for price, I didnt really bring that up as to start a debate on expensive vs cheap. I run all Tuzne pumps and believe that are worth the expense.

I'm not getting into a debate about it, you asked why adjustable flow pumps were more expensive than constant flow ones....

Also, it's predictable in a sense that if you just have two constant velocities of water pointed at each other you're going to always get the same pattern of flow throughout the tank. On the other hand if your two pumps are constantly changing flow rates it creates more chaotic flow.