Theories On Flow - A Few High Flow vs. Many Low Flow

[knowcrap]

I am contemplating updating the flow in my tank and just wanted to get some opinions, see what others are doing and/or think.

Today I have a pair of Seio M2600's, one on either side of the tank. My feeling is that this is limiting my ability to modify my flow as time goes on. Basically two pumps that give a high flow rate are too strong to put ne any coral and at any given time I only have two directions of pushing flow.

What I am thinking about doing is getting 4 smaller pumps (like Koralia 4 or Tunze) that can be positioned around the tank and easily moved if necessary. Besides being smaller and getting aware from the suction cup mounting system the Seio's have I see that smaller pumps have more room to be better positioned as the tank continues to mature as well as the ability to maintain a similar flow rate while dividing the flow rate for more optimal spread.

So...that's what I am thinking...any/all opinions/comments appreciated.

[dots]

I have been contemplating the same thing with my interest in the Vortechs.

I think more, smaller flow PHs for an infinite possibility for flow adjustment and fine tuning to compensate for aquascaping and coral growth is better than one, unidirectional setup IMO. Of course as we often see, there is more than one way to skin the cat.

However, can be more costly, more equipment seen, more potential for problems due to more in the tank, the potential for more heat and power consumption.

I have only Seios and would love to go to the Tunze multicontroller set up, which some intermittint flow to "change it up" is an even better setup.

I have always gotten more/better results when adding more flow and am really interested in flow dynamics........

Have you considered a closed loop system in addition or an Oceans Motions setup?

[tanya72806]

I have a 120g. I had 4 tunze 6100's. 3 of them went out at one time due to need of cleaning. I was away for the week and couldnt take them out to be cleaned. When I came home alot of my SPS looked BAD and lost alot of PE. I sinced cleaned them and working great and the colors and PE came back. So i am a High flow avocate JMHO

[JB NY]

SPS need high flow is a bit of a misnomer. What you need is flow around all of the coral polyps in your tank. 48X turnover means nothing if you have dead spots in your tank, and corals located in those dead spots. One of the reason sps tanks do so well in the beginning is that you have adequate flow everywhere because the corals are so small. After the corals grow large the flow gets blocked and people start to have problems. As long as you can observe the polyps of the corals being blown around a bit you are in good shape.

[knowcrap]

Agreed on all points so far.

As far as "many versus few" my thinking is exactly as DOTS said...as the tank matures and flow patterens need to change for effective flow throughout the tank with the smaller pumps each can be tweaked individually to adjust needs where the need arrises. Since everything grows differently differently I see this as an advantage to managing flow throughout the life of the tank.

Also, having less pumps, even at a higher flow rate, I tend to find there are spots that eventually receieve less flow because I have limited options when directing them.

And I'd love to have a closed loop but with the tank as setup/purchased it would be a lot of work and I am looking at moving to a new tank in the future and I would redesign the entire flow design...my 180 was my first big tank so there was a lot of learning as I went along...probably pretty common.

I generally try to have a less is more philosophy but I think I am going to remove the Seio's and go with 4 smaller pumps (in all honesty I may be after magnetic pump holders!).

But at this point let me ask another question...ultimately are flow controllers better in the long run?

[dhnguyen]

More often than not your aquascape is preventing flow and creating dead spots. Something to look into

[dhnguyen]

Here's my setup for example and I have no deadspots anywhere even with only 2 MJ mods

[knowcrap]

Regardless of aquascaping one should be able to develop a flow that efficiently creates flow in the entire tank, though. That is the core of the question...is using a couple of larger pumps versus using four (really any number of) smaller pumps to achieve this.

We don't have any deadspots *but* there are areas where flow is greater that other spots...again, with two Seio's I feel that I am limiting myself as I only have two directions I direct flow and if I were to get four Koralia 4's I could maintain the same rate of flow while having more flexibility in directing that flow.

In your case you seem to have designed a system that reduces flow obstruction but that is not going to be the case for all tanks.

There are a number of theories on flow and how to achieve a successful flow rate in a tank...I like to hear/see what others are doing to help develop some ideas before droping $$$.

[dhnguyen]

You might find some of these articles regarding a gyre setup for flow interesting.
http://www.advancedaquarist.com/2007/1/aafeature
http://en.wikipedia.org/wiki/Reef_aquarium

[JB NY]

Originally posted by dhnguyen
Here's my setup for example and I have no deadspots anywhere even with only 2 MJ mods

That's exactly my point. When the tank is new and there are not a lot of big corals taking up space good flow is much easier to attain. My old tank after 4.5 years had two strong sea-swirls, a tunze, a seio and two MJ1200.

Here is a pic of when flow started to get challenging.

[Racenrich]

I just upgraded my flow in my 120g....i have a closed loop connected to a OM-4way.

Old setup....1200gph and 4 outputs in tank.
New setup....2500gph and 8 outputs now!

IMO...you just cant have enough flow!!

Kick it up a notch, you wont regret it!

[GSMguy]

Originally posted by dhnguyen
Here's my setup for example and I have no deadspots anywhere even with only 2 MJ mods

Ur tank is looking sweet, What are the black things in the corners?

[chrismhaase]

I guess one question would be how many different powerheads can you stand to look at? I like the idea of multiple powerheads, but sometimes I just don't want to see anymore clutter in the tank. I have 2 Tunze 6000s in my 90, they make great flow but I think that every now and then when I add my old MJ mod or other small powerheads the water really gets moving. hmmm... maybe some nanostreams tucked away might be a good idea.

[knowcrap]

Understanding the general concepts of flow is very important, yet...but also understanding what people are really doing to achieve this is equally important, if not more important.

Thanks for the links.

[dhnguyen]

Originally posted by GSMguy
Ur tank is looking sweet, What are the black things in the corners?

Thanks. Those are DIY overflows made from PVC pipes

[knowcrap]

chrismhaase - I hear you! Next tank will be designed to have a closed loop to provide additional flow so I can get out of the power head game.

For today I do think going to a pair of smaller pumps on each side vs. one huge (HUGE!) Seio on each side I can at least have more options to move/hide the submerssed pumps since they will be smaller.

I am also going to get one of those GS2's as I have an MJ1200 loafing around the house and might as well see what I do with that...I like the idea of those as they are small (placement flexibility) and generate a considerable flow rate.

[dhnguyen]

Originally posted by JB NY
That's exactly my point. When the tank is new and there are not a lot of big corals taking up space good flow is much easier to attain. My old tank after 4.5 years had two strong sea-swirls, a tunze, a seio and two MJ1200.

Here is a pic of when flow started to get challenging.

This is very true what you said and is precisely why I designed my tank's aquascaping so that there is very little rock, leaving room for the corals to grow without significant flow impedance.

[blide]

If you ever get a chance to go diving or snorkeling in the ocean you'll really start to understand the type of flow you really need.
Blasting a coral with a powerhead is nothing close to the real thing because a stream of water is totally different than a wave of water.

[dhnguyen]

blide,

The problem is there is no possible way for us to replicate that kind of flow in our tanks so we have to do with what we have available.

IME, a stream style propeller pump is by far superior than a closed loop in providing that kind of flow.

[chrismhaase]

I agree with the stream idea. Maybe the best way to replicate a natural environment is a Tunze Wavebox.

[dhnguyen]

Well... I personally don't think a wavebox will do it. The ocean flow is more like a mass of water moving constantly not like the short pulsing action you would get from a wavebox.

The key here I think is mass water movement, not a stream, not a squirt, not a pulse. The idea of the gyre is that the pumps ,setup in a circulating (gyre) placement, are on all the time utilizing the existing flow momentum to speed it up even more thereby generating this mass water movement through friction and turbulence. Kinda like how stirring a pot of water in one single direction will create a mass movement of water.

One other way to achieve this mass water movement would be to use a large surge device of some sort. But this can be complicated to implement.

[knowcrap]

Actually, I am thinking about experimenting with the Gyre concept...loosely of course.

Basically I would like to place all of the pumps at the top of one end of the tank (probably the top) and have all the flow push in that single direction and see what the flow looks like as compared to having the flow "meet in the middle" by splitting them equally on the ends of the tank. I am also thinking about lining up the pumps along the back of the tank, pushing the flow from back to front/top to bottom (as opposed from side-to-side or end-to-end).

Maybe folks have tried this...I like to experiment.

(And if I can pull it together I would like to video tape the various experiements.)

...and dhnguyen, do you happen to be the person from Kingston, WA I sold my old Hamilton 400W ballasts to? I just a ferry ride away.

[dhnguyen]

Yes I am the same guy Had a feeling that your RC name sounded familiar

Ballasts are working great BTW... Thanks

[knowcrap]

Well there you go...small world!!! It was your love of MJ Mods that gave it away!

If you ever take the ferry over and want to stop by and see some flow experiments...let me know.

[dhnguyen]

Likewise dude. If you're ever planning to go over to our side of the pond, let me know. I could show you MJ mods that will blow away that SEIO 2600