Help me understand "flow"

[d2mini]

Ok, so I understand flow when pertaining to GPH.
My pump/overflow on my 46g is probably circulating the water at close to 400gph, so around 8-9x would be safe to say.
But then I hear about people adding more flow my using powerheads in the tank and this is where you lose me. How do you even measure this kind of flow and how does it compare to the main system flow using the pump/overflow? For a reef tank how much flow overall should you have? I've heard as little as 4x and as much as 40x! :shock:

Secondly, considering my current setup, what size Koralia would you recommend and how many?

Thanks!

 

[yote]

Well.
GPH is just a general term used to describe flow.Most folks want roughly 10X turn over through their sump,But thats different than flow in the tank.
The flow in the tank keep waste washed off your corals and hopefully keep detritus in suspension long enough for it to be removed from the tank.That being said.You want enough water movement in the tank to reduse or eleminate and dead spots where crud can build up
In a 46,I'd go with at least a couple of the #3s,probably even #4s.As long as your sands on the bottom,you dont have too much flow.

 

[jkeating2005]

i have 2 koralia #3's in my 46g tank it seems perfect flow wise!

 

[dustin_P74]

well it may seem perfect to you but its what the corals want. if you go sps you want very turbid water flow but if you go lps then you want a more subdued tank. and the way you measure your GPH once you start adding pumps is look at what the koralia box says it puts out in an hour, i know the 4's pout out 1200gph. in my tank i have 10x turnover from the return and then 3 koralia 4's so now im at 40x and then i added the vortech today and that is pushing 3600gph i believe so im pushing 70x when i have everything turned on to the max setting and my sand bed is fine

 

[d2mini]

Wow!

Ok, well I'm glad I asked cause I was thinking of getting no bigger than k-2.

And thanks for clearing that up.

Do you think 2 k-3's would be too much for a mix of lps/sps in my small tank?

 

[dustin_P74]

not at all

 

[reeffreak]

Two K2 will work fine too.

 

[simpleman]

I have 2 K2's in my 55 and everything is happy. It's a mix of LPS/SPS

 

[Bifferwine]

I think two K2s would be great in your tank. If you are planning on adding SPS, maybe one K2 and one K3?

 

[jhnrb]

For total g/p/h (gallons per hour) flow you can just use the pump ratings. it will be something a bit less but you will be in the park. the amount of flow depends on the type of pumps, the aquascape, and the type of animals. then there is the turnover rate (amount of water that goes through the sump every hour) you should try to get at least a turn over rate of 4x, and a circulation total to give your system a good chaotic flow as possible with no linear flow directly on the animals/corals. good luck hope something here helps.

 

[d2mini]

Thanks for the help.
I don't mind spending an extra couple dollars to buy the 3's over the 2's.
I just don't want to end up with TOO much flow, if that's possible.

 

[dustin_P74]

youll know when you have to much flow because the sand wont stay on the bottom, but i dont think youll have that problem with the threes

 

[beano]

since chaotic flow is the goal, is a wavemaker the best way to achieve random flows? i would imagine that any number of powerheads , unless alternating, would eventually create a patterned flow (i took chemistry instead of physics in college).

 

[Altohombre]

I had 2 #3's in my 46 and it was like a wind tunnell. Crap was blowing everywhere. I finally adjusted the only way I could which was both facing up towards the surface, however my LPS were still swaying around like crazy. I eventually went to just 1 #3.

 

[yote]

since chaotic flow is the goal, is a wavemaker the best way to achieve random flows? i would imagine that any number of powerheads , unless alternating, would eventually create a patterned flow (i took chemistry instead of physics in college).

If the powerheads are pointed so that the flows meet,it causes the currents to crash together.That helps keep it some what chaotic.A wave maker will do a fine job,but a lot of the power head arent designed to wotk with them,

 

[d2mini]

If the powerheads are pointed so that the flows meet,it causes the currents to crash together.That helps keep it some what chaotic.A wave maker will do a fine job,but a lot of the power head arent designed to wotk with them,

What would work if I wanted to get a wavemaker in the future?
Or is it not even necessary and more of a cool toy?

 

[dustin_P74]

its a kool toy, and if you want one in the future just by a wavemaker, they usually come with one or two powerheads depending on what you order

 

[yote]

They are a cool toy.But they are also good for a lot of coral.SPS especially like the flow patterns a wave maker creates.
http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+4588+18915&pcatid=18915

http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+4588+12061&pcatid=12061
The last one will work.But a lot of the powerheads will kick backwards for a few seconds when they first come on,and the clicking they make get annoying pretty quick.

 

[dustin_P74]

im not a maxi jet fan, i would go with the koralias