Let's Talk About Water Movement in an SPS Tank.

[coralite]

I spent a while this summer analyzing flowrates within a respirometry chamber. The chamber is equipped with a volumetric flowmeter. To calibrate the volumetric readout with linear flowspeeds within the chamber, I videotaped the velocity of hydrated artemia cysts with a digital camera,with a scale bar in the frame, and then I simply traced and timed the path of the cysts in slow motion. Artemia cysts are preferable to flake food as they are neutrally buyoant, will feed your corals and it wont foul your tank like flake food. If anyone is interested in trying it out, I would say 10-20cm/s is about right for a stoney coral tank and above that is a really high flow. It is important to make measurements near the corals and reef structure in general cause flow is going to vary quite a bit in the tank and a coral doesnt care if there's 40cm/s coming out of the pump if the flow around it is 5/cm/s. If a large branchy coral has 5/cm/s around it, then the flow will be even less between its branches.

[prop-frags]

Originally posted by AlgaeMan
I just added a Tunze 6200 and was very impressed with the results. My tank is 6' and I had to turn the thing down to 30% and set on/off every 10 seconds. I was using two 6000's, but the corals have grown a good bit and there were more and more dead spots. So now I'm using a 6000 on one side and 6200 on the other.

Algaeman, I've got a 6' AGA 125 RR tank:

It's a bit hard to see in this pic, but I've got 6 returns plumbed. 2 returns are closed loop, and the other four are from two return pumps in the sump. I've gotten rid of most of my softies, and am feeling more confident now about ramping up on SPS. I feel like I've got good flow across my rocks, but am thinking about adding a Tunze Stream for some flow across the front. With your experience using the 6000, would you suspect that would be the right model for me? My (somewhat outdated) plumbing diagram is in my gallery.

[prop-frags]

Let me ask you guys. Here's my plumbing diagram:

My original design idea was to prevent the need for any powerheads in the tank, and now I want to jack up the flow a big more. What would you advise? Can I do it with the plumbing that I have? Add Oceanmotions or Seaswirls? Add Tunze Stream?

[trmills]

Mike,

IMO, pipe size to and from the tank should be either a minimum of 1" or at least one size larger than your bulkheads, especially on any returns. That will help maximize flow by minimizing friction losses. Reduce them at the pumps and bulkheads. If this tank is not set up yet, I would consider utilizing 1-1/4" bulkheads for every hole. Much better to have excess capacity and not need it than limited capacity and need it.

Use check valves that are larger than the pipe it is installed on (i.e. 1-1/4" or 1-1/2" on 1" pipe). I have been doing that for over 8 years. Once a month I shut off my pumps for an hour and check my sump level. I have never had leakage using this method. I have them mounted vertically and horizontally.

BTW, your tank size of 72"x18"x24" is 134.6 Gallons like mine. HTH.

[Bugger]

I would just like to point out the reason why you need so much current. Food particles such as bateria plankton and other organic stuff in your tank become more readily avaible when you get things flowing.

[ReefDream]

Just to warn those who might be considering the Seios as a means to induce lots of current with little power: I bought three 820s myself. All of them jammed with calcium build up in a matter of eight weeks. I cleaned them the first time without trouble, but they bound again (and worse) in a matter of a few weeks. Now in my tank I use a lot of kalkwasser for induced evaporative loss (3 gallons a day for a 120 to cool the tank), so I forgive all pumps and power heads for jamming to some degree (although these were far worse than the Maxijets they replaced in this regard). However, there is something far, far worse about the Seios than just jamming.

The problem is in the ceramic shaft and glide washers through which the shaft glides. Their shaft is made of ceramic and is therefore extremely easy to break during cleaning. Since cleaning a jammed powerhead or Seio almost always involves freeing the shaft with vinegar or muratic acid and using some degree of force, it is almost impossible to clean them without breaking the shaft. Furthermore the washers on which the ceramic shaft glides are also made of ceramic, and two ceramic surfaces very close can weld together very easily with calcium (calcium loves to bind to ceramic). The weld can become very strong too since the Seio CAN work with these two parts bound for days. What essentially happens is that the shaft and the magnet rotate as one, and then shaft ends rotate, with considerable friction, in the shaft end shoes. This is not a stable or efficient operating mode, though, and sooner or later, the pump will stop completely once the shoes also bind. With the shaft bound to its ceramic glide washers, there is no way to get acid to work in to the near microscopic gap filled with calcium between the ceramic washer and the shaft. Soaking it free is your only option (forget freeing it with force as that will just shatter the shaft), and even soaking might take days to work.

Essentially, these pumps are poorly designed since they cannot cleaned without breaking the ceramic shaft and are designed in such a way as to encourage jamming up. These pumps should be avoided at all costs if you have a high calcium tank, like those required for a high growth SPS tank.

[JB NY]

Thanks for the heads up. I have a Seio 820 running in my tank for about 16 weeks with no lockups. I give most powerheads about 4-6 months before they need to be cleaned in an SPS tank. But so far I have not had any problems with them.

[ReefDream]

The point is here, JBNY, you SHOULD NOT LET THESE SEIZE before you clean them. If you wait until they seize, you may not be ABLE to clean them no matter how much acid you use. I have one ceramic shaft welded together with the ceramic washer that has been soaking in pure muriatic acid (which is much stronger than vinegar) for days and it hasn't loosened up a bit! Once the two parts are welded together, the gap between them is so microscopic that the acid cannot enter it, and any applied force will crack the shaft. This is a major design flaw.

I recommend anyone with these pumps to take the minimal period of time a typical powerhead must be cleaned in your tank (in your case 4 months), shave about 1/4rd off of that (say 3 months for you then) and soak the shaft and magnet of these pumps with that frequency so they never seize. If you do not follow a proactive cleaning regime on these, you risk ruining your pump. I ruined two pumps now by allowing them to seize before I tried to clean them, and I am sure I am not just some fluke.

[JB NY]

point taken.

[MiddletonMark]

A wise point with any pump or powerhead.

It's easy to not clean them regularly - and every pump will last longer and possibly run better when kept clean. I've been amazed to clean my pump and realize that it wasn't supposed to be that loud, I had forgotten how quiet it was at first.

[coralite]

ReefDream, I think your experience may be particular to your water chemistry. In systems that use a lot of Kalwasser for top off the systems tend to run a higher pH and have higher Ca levels, therefore, your system tends to precipitate a high amount of Ca. Calcium precipitation is a much more affected by water chemistry than substrate chemistry and i dont think the material of the seios is to blame. For more info on the topic read RHF's article in RK this month.

And you mention that the shaft is made out of ceramic like that would make it weak when in fact ceramic is very VERY strong. Maybe you should stop soaking your equipment in muriatic acid because anything that hasnt reacted with the acid within 15-30 seconds is likely not supposed to be dissolved.

I have been runing a seio 820 for several months and have not experienced this precipitation on my pump at all, but then I dont add any CaOH to this system

[dufferdan]

I am looking for feedback on my OM 4way Squirt closed loop plan on my 20L. I posted a drawing in the members gallery.
This tank will be bare bottom for SPS dom.
I not sure of the best placement for the outlets.
Cheers

[ReefDream]

Yes, ceramic is very strong in one sense: it is very hard. However, it is also brittle. In general there is a tradeoff in many materials between brittleness and hardness.

I do soak my main pump (Iwaki) magnets every six months as otherwise the magnet inside will experience considerable resistance due to calcium buildup (and the water heats up as a result). While a cleaning period of every six months is a acceptable to me, every few weeks, as in the case of these Seios, is not. Also, no other pump I've every seen--and being in the hobby for about 10 years I've seen many--is prone to shatter easily during cleaning. The Seio shafts should be replaced with a suitable metal in my opinion, so force can be applied to dislodge it without shattering it.

[yellowtruck75]

We need to get this thread going agian.

I need some opinions, I am about ready to buy my closed loop system and I wanna know if it is the best I can do without buying Tunze streams. For my 125, 6' SPS/Clam/LPS tank I was thinking of adding a 4 way Oceans Motions system run off of a Sequence Dart. I am gonna put the 4 outputs at each corner and point them slightly towards the center.

This is a large investment and I wanna make sure that I am buying the best setup I can get. I don't wanna have to upgrade this is the future. Also the Sequence Dart will be sitting level with the tank so there were be very little head pressure.

How does this setup sound? I want optimal growth and color out of my SPS. Are there any suggestions for a different setup that might be better? I have done alot of research ont his and this seems to be the ticket.

[yellowtruck75]

Would the added flow have an effect on my dual over flows?

[herbert4]

From what I have seen, the OM is a great system and the sequence will work great with it. I am setting my tank that same way.

Would the added flow have an effect on my dual over flows?

The flow will not have an effect on the overflows. The Closed Loop is just what the name says (I know it really stands for closed to the air ) but the volume that it cycles stayes within the tank. For a visual, It would be like sturring a glass of tea with a spoon.

HTH

[cediss]

With regards to Cozumel, my guess would be that those reefs are a very different sort of environment than the niche we commonly try to mimic. I remember mostly massive stonies at Cozumel that form huge mounds or globes (like a closed brain coral) mixed with many gorgonian and other life. I think the pacific sps corals we keep desire conditions more similar to the A. palmata (elkhorn) and A. cervicornis (staghorn) corals in the Carribean that grow best in the turbulent breakers or other areas with variable flow. Not sure if that is correct but it would be my guess.

Having been to Reefs in Fiji and Hawaii I can say by experience that Pacific reefs vary dramatically in current velocity, direction, and force. Even in cases where the current generally flows in one direction, it will often reverse direction hours later as the tide flow reverses. This is more typical for backreef margins by the nature that the currents travel through channels both upon entering and exiting the reef zone. For the surfers out there its similiar in principle to a rip tide.
Forereef and reef crest margins will tend to be more violent, with currents crashing into SPS and flowing in multiple directions. In each zone there are species that are specifically to adapt to its own niche in that zone. Some SPS will grow in a variety of zones and others will grow predominantly in one zone ("survival of the fittest"). That is one reason for the variety of SPS we see.

Different SPS are adapted to different types of currents. Generally finer branching (thinner) SPS grow is less velocity and Thicker SPS grow in higher velocity. Many will atest to this by experience where the morphology of the SPS changed when the velocity changed ("Birds Nest" hystrix is a great example).
And, just like the corals grow and change shape, so to does the reef itself resulting in currents changing. So just as we struggle to prevent dead spots, nature does as well. Only its a hurricane or sunami that rearranges the coral.
In conclusion, experiment with currents, paying careful attention to how the coral responds. Learn about your SPS species. Is it found on the forereef, crest, backreef or all the above. Once you know this you can decide what kind of light and current it needs. Be willing to thin your corals out if necessary to allow more flow. This is what keeps this hobby interesting and challenging. The more you know about each of your SPS species the better suited you will be to propagate it.
I generally feel that after considering what area your SPS species comes from, try to mimic this environment. You generally wont go wrong with currents that change direction frequently. What's probably more critical is the velocity. A. humilis is generally found, for example, on reef flats and exposed upper reef slopes. For this reason it tolerates and prefers higher velocity currents. While A. pulchra tolerates and prefers lower velocity as it grows in the backreef margins.
In the end, current is current, just as wind is wind. Each device used to produce it has advantages and disadvantages(purchase cost, operating costs, maintenance and reliability to name a few). As an example of this, I went on vacation last year for 2 weeks. My mom knows generally what signs to watch out for in terms of system failure and she stops by every couple days to check to see there are no leaks, and that the system is running. But as Murphy's law would have it (or Entropy) my Sea Swirl jammed sometime during the vacation. All other systems and parameters remained constant. Just the flow became less multi-directional. As a result I lost 3/4 of my purple A. samoensis colony that I had raised for 3 years from a 4" to an 8" specimen. When I discovered this I immediately fragged the remaining healthy branches. Fortunately, I still have these frags which have grown together to reform one colony. It to is now about 4" in diameter. I also found my leather coral had began to deteriorate with a hole in its center. Re-establishing current has corrected all problems. Reliable equipement and frequent observation is necessary if you want to ensure success in marine aquariums.
Remember KISS (Keep It Simple Stupid). Generally the less sophisticated your equipement the better. This doen't necessarily mean don't spent money. Just cosider all options. PH's, SQUIDS, and closed loop systems are a great place to start.

[yellowtruck75]

^

[Bomber]

You know something?

Water movement keeps a area clean for coral settlement and development mostly.

[richfavinger]

What are your thoughts on the use of Tunze Stream 6000's on a 75g? (Was going to use 2 till I upgrade to a 120) Too much? I thought about the Tunze 6000 because they have speed control, of that I assume the wave maker (Tunze) would slowly bring power up / down.. As the other Tunze's do not have speed control? So they are just ON or OFF? Correct?


Thoughts please...!
Rich

[herbert4]

Yellowtruck,

I was thinking more and have a question. How are you planning on plumbing the CL? If you are wanting to use flow from the overflow than it will effect it. If you are using different intakes for the CL that is seperate from the Overflow then it will not.

[JB NY]

Those pumps will work fine. Actually in a newer tank most pumps, closed loops and powerheads produce enough water movement. The problem ends up being down the road. The corals grow and cut off the flow to other corals. That's when you need to pay attention to your flow and make adjustments.

[yellowtruck75]

herbert4
I will be using an over the top intake for my closed loop so i guess there wouldn't be any impact on my overflows. Does anyone know if an Oceans Motions 4 way will fit fully plumbed in a 4" space? My tank is only 4 inchs from my back wall. I was gonna put my Sequence Dart next to the tank and locate my OC in the middle of the back of the tank.

[LittleBlueGT]

Originally posted by yellowtruck75
herbert4
I will be using an over the top intake for my closed loop so i guess there wouldn't be any impact on my overflows. Does anyone know if an Oceans Motions 4 way will fit fully plumbed in a 4" space? My tank is only 4 inchs from my back wall. I was gonna put my Sequence Dart next to the tank and locate my OC in the middle of the back of the tank.

I don't think the 4-way would fit in only 4 inches of space. Mine takesup almost 2 feet once you consider the 1.5 inch plumbing and gradual bends in the pipe. Even with smaller more restrictive piping it still wouldn't work. Try mounting the unit on top of the tank.

[yellowtruck75]

What about using 2 sea swirls instead of the Oceans Motions? How would that be when it comes to flow and different currents. 1 at each end.