To much flow?

[Dave VG]

Is there such a thing, short of blowing the sand around? Anyway, I was thinking, what if I were to buy two return pumps for my refugium setup at say 550 or higher each and put the returns one at each corner in the back of my tank where you would normally put the power heads, thus eliminating the power heads altogether. Nice clean look. Or maybe running a scud on each return line and putting one return front and one back on each side. Would like to hear your thoughts.

Dave

[jacksonpt]

No, as long as you're not causing a sand storm or blowing corals off their perch, there is no such thing as too much flow.

That said, some corals prefer less flow, so keep that in mind. Ultimately, as with so many other factors, what you plan on keeping will dictate the proper equipment/setup.

[RyanM]

Id have to say yes, there is such a thing as to much flow. Even corals that like alot of flow can have to much. Nothing likes being hit by direct flow. As far as using 2 return pumps, I think if you planned it right you could use 1 and plumb it to both sides. There is pro's and cons to both 1 or 2 pumps. 2 pumps use more electricity take up more space and create more niose than just one. but if you have 2 and 1 goes down then your still moving water. But again id say yes, there is such a thing as to much. You can always dial it back with a valve tho. I would make sure to put valves on your returns.

[nwrogers]

Depending on the coral there is such a thing as too much flow and there is certainly such a thing as too much direct flow. I don’t think having two return pumps is the way to go. If anything you would just have one a T it off so it goes to two different sides of the tank. I would also advise you to not use your return pump to design your flow. It is ok for it to supplement your flow but if you are going to use it as your primary flow you will be asking for problems with micro bubbles and noise. Just to give you some numbers IMO you should have between 25 – 40 times your tanks volume in flow. Now those numbers are gross generalizations just like the watts per gallon baloney and all of the other advice we, including myself, usually give to people just starting out because typing is a pain. But Dave because I like you and I think this is an extremely important topic that may help others I will attempt to give you what I consider some excellent advice…

It is not how much flow you have but what you do with your flow that matters. Setting up and carefully planning your flow is extremely important IMO and is one of the most overlooked parts of our reef tanks. In the ocean corals receive mostly random chaotic flow in the form of oscillatory surge. So duplicating this in our reef tanks should be our ultimate goal as far as flow is concerned. One way I often see aquarists setting up there flow is to have some powerheads on the back glass pointing towards the front and banking it off the glass. This however is an inefficient way of creating random flow because as soon as the water hits the glass on the front of the tank it loses most of its momentum. Another better but still flawed way is to setup two powerheads on either side of the tank and have them both blasting towards each other colliding in the middle. Although this is better IMO it is still not ideal because anytime your flow hits an opposing force it looses its momentum and effectiveness. So what is best you are probably wondering? Fast laminar flow that follows a circuitous path. Yes that’s right, unidirectional flow! So why should you blast your flow in one direction, how is that random or chaotic? Because as soon as the water his an irregular surface such as live rock or a coral it will become both random and chaotic (aka turbulent). OK so what is the best way to setup laminar flow that follows a circuitous path? Well the best way to do this is to try and duplicate what is called a gyre tank in your home aquarium. What is a gyre? A tank with flow just like a big old toilet bowl! It spins the flow fast one way and than 5 to 15 minutes later, depending on the size of the tank, it reverses the direction of the flow. All it takes to do this is between 2 – 4 powerheads depending on the size of your tank. One powerhead is on and one is off if you are only using two. You just angle them to make the water go around and around just like a toilet. Then turn on the opposite powerhead and send the flow back the other way. If you have four than you do the same thing except two are on and two are off. The two that are on are working together to spin the water like a toilet. Just remember the most important thing is to increase the overall water flow speed so you can increase turbulence which in turn will increase gas exchange and rates of photosynthesis and respiration in your corals. Did you get all of that Dave? :) Now I know this may seem like some pretty out there stuff for some people so I will include one of my references for everyone to read…

Feature Article: Water Flow is More Important for Corals Than Light, Part V
http://www.advancedaquarist.com/2007/1/aafeature/view

Hopefully this helps answer some questions and give you some direction for setting up your flow.

[Dave VG]

Thank you Nate for taking the time to respond with a full explanation and not short cutting it. I really appreciate it and think it will be a good source for myself as well as for other people starting out or maybe even for some experienced reefers. I think I understand the concept. I think lol. So in essence you are you saying to use a wave maker system? I could do that. So per your advice I will use powerheads to achieve this flow. I’m looking at two of these http://www.petsolutions.com/Seio+Super+Flow+Pump-I-10600999-I-C-42-C-.aspx the 620 or 820 model. These should be good enough I think. I could get two timers to turn on and off at whatever intervals I need. 15 min then rev for 15 min and so on. That should work. Right now I have 2 Powersweep 228 Powerheads at 270 gph pointing strait at each other one on each end right now(and they are sweeping) and one Penguin powerhead at 300gph in the middle of the back pointing to the front. I don’t think I have any dead spots. At least the food does not seem to settle on the bottom anywhere and stays suspended. But I just don’t think its enough flow. So what do you think. So how many gph for the return pump and does that contribute to the flow figure. I have read that the turnover should be 10 or 15 times the volume.
Thanks
Dave

[drbronx]

Thanx for excellent reference nate. Now I just need time to read it thjoroughly.

[Dave VG]

Just got a chance to read your link. Very informative. Thank you Nate.


Dave

[nwrogers]

Dave I think Seios are really nice pumps but you cannot use them on normal wave timers. You have to buy their special timer that is pretty expensive. You could try some mjmods and they may be a bit less expensive. I think depending on how far you want to go in creating a natural reef environment you may want to use a wave timer. Could you get away with two seios on all of the time? Yes and your corals would be fine. Would they do better if they had a pimped out wavetimer system? Yes you would probably see faster growth and they would do better as they got larger and their demand for good flow increased. You can always start with the less expensive option and work your way up but I just wanted to expose you to the ideal situation and you can make your decision from there. There are many people with beautiful tanks and very healthy corals without wave timer systems. Your return pump should move between 700 – 1000 GPH depending on how you plumb it and if you decide on peducators and/or a SCWD.

[drbronx]

I managed to read the thread posted by Nate. Very informative and many excellent points. Basically, he's saying, "its not the size of the ship but the motion of the ocean":) I believe that in general, aquarists, including myself have not payed enough attention to flow issues and its good to see that it is commanding more attention. I would say the major flaw in my own 125 gallon sps dominated system is improper amount and type of flow. When my corals were small, it didn't appear to pose a problem. But now that my corals are much larger i can observe the effects. Parts of the largest corals that don't receive much flow tend to bleach. These are usually the lower branches that are blocked from flow by live rock or other corals. Also, the corals placed away from high flow areas grow much thinner branches. Some other corals who receive too much direct flow show signs of recession and necrosed tissue. Now with the advent of closed loop systems, wave timers, and more sophisticated power head designs, we can design better flow systems. Of course that can get expensive. I'm thinking that were i to correct my system I would get a couple of maximods on a wave timer and add at least one Sea Swirl to the return lines. Of course if i was starting from scratch, then closed loop with a couple of sqwds or the Motionsoceans 4-way loop would be the way to go IMO.

[Dave VG]

Thanks Nate and Jerry. Jerry that’s really good info also, thanks. I am reading up on whatever I can find about water movement setups. Not a lot out there tho. Still googling as we speak. Mostly company’s selling there stuff. It is actually very cool area of reef keeping. I really want to try and do this right the first time. That is until there is a new theory or some new product that is lol.

Dave

[Dave VG]

Ok, so here’s what I’m sure of so far. I think lol. I will keep my current powerheads and take the sweeper mechanism out. I will control them with a Natural Wave Wavemaker controller for now(cheap enough).
I will get a mag-12 for the refugium return to the tank. That will give me a little extra as for as flow. It should give me approximately 1100 gph at the top of my tank which is four feet.
Of course sand to replace the crushed coral substrate.

I will probably upgrade to two Seios 1100’s paired with a Seios wavemaker controller at a later date. Should work nice in my system. It is as Nate said, an expensive and preparatory system as far as the controller goes.

That a good cleaning and getting parameters right by dosing should have me ready in no time for SPS and maybe an LPS or two.

[nwrogers]

Sounds like you have a good plan now. One thing however, unless you are going to use a SCWD and/or penductors that mag 12 is too big for the overflows you have. You would be better off with a mag 9.5

[Dave VG]

I will change that Nate. Thanks for the heads up. Could I possibly valve the flow down a little. That way if in the future I were to use a SCWD and/or penductors I could. If not I will change that to a the 9.5.


Dave