Closed Loop Design "comment please"

[Mouse]

Ok, this is how i see the closed loop system for my new tank. Its a bit outlandish but im sure you can see the reasons behind the design. What i would like to know is what you guys think of it, could it be done better, simpler.

Top priority is to have as little inside the tank as possible, whilst still providing a very functional system.

 

[Adam1]

Mouse,

I run a closed loop and love it, and am glad to see them becoming more popular. I see two things in your system I would be concerned with.

Fist, your pump intakes will be quite dangerous to passing animals, especially wandering anenomes, cucumbers, starfish, etc.

Second, even with 1/2" sea swirls, you will probably be dissapointed with the flow, even if you eliminate the jets coming out of your overlow and just run the sea swirls.

I have two 3/4" models running on a closed loop with a 2100 GPH pump, and I am considering increasing the pump size. By the time you account for the elbows you use, plus the twists and turns inside of the sea swirl, you have lost alot of flow.

HTH

Adam

 

[Mouse]

The intakes should cause no problem to passing animals because theres four for each pump and even if three of the four were completely covered the remaining one should be able to handle all the flow. Hence the manifold configuration

the sea swirls are the 3/4 models.

with regards to lost flow i thought the fact that it was a closed loop would eliminate any head pressure.

[ May 09, 2002: Message edited by: Mouse ]</p>

 

[wade1]

Have you asked about or considered the structural ramifications of having so many holes in series on the sides of the tank? Seems like that many may make for some serious reduction in resistance to the force the water puts on the tank sides...

Just something to think about.

Wade

 

[Mouse]

Thanks Wade, i was hoping the guys who are going to make it for me would point that out if it were a problem. If so then i could alternate the height of the side intakes untill a comprimise was reached.

 

[Anonymous]

hi.
My reply got trashed when MC shut down the BB for upgrade... .

I was trying to say that there is a difference between static pressure (none in a closed loop system), and dynamic pressure (cause by friction of fluid moving thru conduit and small orifices).

Another thing that I was trying to say is to make sure you have enough space inside the overflow for the installation of the bulkhead/elbow/pipe. Does not look like you have much room to play with there.

 

[npaden]

I think you could accomplish this much simpler by using larger diameter plumbing and fewer intakes and outputs.

My rule of thumb is 400 gph for 3/4"; 750 gph for 1"; 1,500 gph for 1.5" and 3,000 gph for 2" for both intakes and outputs. Actually lately I've been thinking of reducing my recommendation to only 350 gph for 3/4" as they are just so small they have suction problems on the intake sometimes even at only 400 gph. All of the above flow rates equal about the same velocity through each diameter pipe.

I would just put 1 - 1 1/2" intake on each side and run that to your output configuration as you have it. I personally would prefer a 1" swirl and a couple 1" static returns on each side instead of your setup unless you are going with the 3/4" swirls because of the louder motors on the 1". (BTW, they are beta testing a nearly silent motor on the 1" models)

I think 1 swirl on each side along with having the static returns pointed toward the center or toward each other in an intersecting pattern would create plenty of random currents for you. If you wanted to prepare for even more flow down the road if you needed it you could go ahead and put in 2" bulkheads for the intakes instead of the 1 1/2" but I think the 1 1/2" would be fine for the intake on a 1,500 gph pump.

You still have friction losses in a circulation loop so you want to use the largest size plumbing you can to cut down on this. You would be amazed at how much using 3/4" plumbing on a setup like this instead of 1 1/2" would cut down on your overall flow.

My rallying cry lately has been "Maximize Flow, Minimize Velocity" and it really is true.

FWIW, Nathan

 

[Mouse]

Nathan thanks for the reply,

Im surprised you suggested just one pump inlet on each side of the tank, the reason why i have four on each side is so that should any of them become blocked with beasties, the remaining pump inlets sould comfortably be able to handle the remainder of the flow. Am i correct in thinking this, or are there no benefits to this method?

I would just be a little concerned that with only one pump inlet each side of the tank that should an anemonie park its gelatonous ass over the strainer the pump will suck it up and shower the reef with poisonous blamonge. But the chances of such an occurance with four pump inlets on each side would be allmost incalculable (touch wood).

I was thinking about making the side pump inlets 1" bulkheads, these would then connect to a 1 1/4" pipe that would connect to the pump. For the outlets 1" pipe coming out of the pump and then reducing to feed the 3/4" sea swirls and the 1/2" outlets protruding from the sides of the overflow chamber.

If you think that the plumbing will create too much dynamic pressure and cause a significant pressure loss i could go for a 2000GPH model pump on each side of the closed loop. The computer i intend on using has the facility to throttle back on pumps, so i guess if they were that little bit too powerfull reducing the throttle on the pumps can only provide additional benefit through loss of impellar sheer, therefore creating a safer environment for Zoo's, Phyto's and other microscopic free floating doobries. Also the larger 2000GPH pump uses the same connection fittings, so the plumbing size will reman the same.

So what do you think:

• Summary.
  
  Flow Out to Pumps
  
  4 x 1" bulkheads in each side of tank
  Each 1" outlet will have a union ball valve for flow controll & disconection of manifold if neccessary.
  These four 1" pipes connect to the main 1 1/4" pipe that feeds the pump

• Flow In to Aquarium
  
  1" Pipe from pump
  Split to 3x 3/4" pipes to feed two 3/4" Sea Swirls and the overflow nozzles.
  The 3/4" outlet to the overflow nozzles will split to form 2 x 1/2" to feed each nozzle.

There will be varous flow controll devices to ensure desired distribution of flow between each of the sea swirls and the overflow outlet nozzles.

I have chosen to use four 3/4" Seaswirls insted of two 1" Sea swirls because of the noise. And i also feel that this configuration will provide a more varied chaotic flow.

Help is much apreceated as i hve decided to buy the tank first and then all the other equipment will come as and when. I really want to get everything decided and nailed down before i ring numb nuts at the LFS. I dont want anyones opinion other than those who care, like you guys.

 

[Mouse]

hello, just testing :?

 

[Entacmaea]

Hey there, sounds like it will be a great tank! I probably agree that you will loose more gph than you think, so the upgrade to 2000gph pumps is probably wise. Just wondering from what side(s) is the tank going to be viewable? If only from the front, that is fine, but if from three sides, I would plumb the intakes through the bottom, put screens over them, and hide them in the rock work. The lower the intakes, the generally less oxygenated water they will be cycling back up to the surface. On that large and lovely a tank, it would be a shame not to be able to view it from more than one side! But if it is a wall installation, well, I guess that is alright then! :wink:

Best, Peter

 

[Mouse]

It was mainly going to be viewed from the front. But you should have at least 15" of clearance and viewing space obove the pipes. I could put them in the back of the tank i suppose, but with it being so wide im worried about firstly being able to get it through any doors, and secondly i wanted as much of the pipe joints to be in view (leak paranoia).

Plus im a bit of an industrialist, so loads of pipes and stuff would look cool.

 

[Anonymous]

Hey Mouse-
Looks great! One thing that concerns me is the very low placment of the intakes. I think the average reef tank recieves a vigorous enough mixing that stratified layers and such is not really enough of a problem to justify the added severity of results should a leak occur at one of the low spots. I'm paranoid, though...

 

[Mouse]

Sorry Dan, didn't quite catch what you meant there. I get your point about the circulation over the sand bed being strong enough. But did you go on to say that you also think its a bad idea to have bulkheads so low in the main aquarium. If so i would have to agree, thats why i origionally thought of putting the bulkheads behind the overflow box with the stockmans. But apparently this would cause me problems in two ways.

Firstly the current would be so great that surface skimming would no longer be effective. And one of my main criterea in the design of this tank is that its run on a "no-escape" method with regards to how the equipment is set up. This basically means that the skimmer will be hard plumbed into the Stockman standpipe. So it will mean that what ever is skimmed off the surface will end up directly in the skimmer fraxination chamber.

Secondly the size of Overflow would be huge to accomodate the total flow of both circulation pumps and the sump return.

This has brought me to the opinion that if these pumps have to be fed from bulkheads directly plumbed into the aquarium itself, they may as well be utilised as effectively as possible in directing flow to where its most needed. The sand bed will be about 3" deep in the main tank and then the pipes will be about 10" above that. So i would have about the same ammount of clearance above as below the pipes, Hopefully this will result in the circulation system being free of air.

 

[Bio]

Curious on to which software you used to create the above design.

Planning on a new system and would love to create a similar design for review by other board members. :?:

 

[Anonymous]

Sorry, run on sentence! All I meant was, if a leak occurred in the plumbing the tank water could drain down to the level of the lowest drilled hole. If I was doing a closed loop I think I would try to have the holes, and if possible, the pumps and all the plumbing mounted higher.

 

[Mouse]

Dan, i follow your sentiment exactly, but its a weigh up between empty tank and one full of bubbles.

Big, i used Corel Draw 9 to make the picture. I do DTP for a living so it wasn't to hard. But any drawing package should be able to produce something simmilar. I have seen fully 3D rendered designs before and they look soooo cool, but unfortunately a little beyond my grasp.

I forgot to mention that all GPH ratings are for Imperieal Gallons and not US Gallons.

A better way to describe the flow in this instance would be 15 x total aquarium volume per hour. So ive allready gone a bit OTT, does anyone still think that the 2000 (UK)GPH pump would be needed to overcome dynamic pressure?

im looking at £383.70 for the 1500 GPH, and £441.95 for the 2000 GPH pump. Considering the 1000GPH pump is £199 i dont think that an extra £60 per pump is too bad a price to pay considering the extra power ill get. MMMOOOOOOORRREEEE POWER :twisted:

 

[IcantTHINKofONE]

I was thinking about 2- 3/4" sea swirls at the end of my closed loop system pumped by a 1200 or so GPH pump. Now in this diagram I see that there are holes in the overflow box halfway down which shoot water to the middle of the tank. Do I need that kind of water flow in the middle of the tank for a FOWLR tank?

 

[IcantTHINKofONE]

I was thinking about 2- 3/4" sea swirls at the end of my closed loop system pumped by a 1200 or so GPH pump. Now in this diagram I see that there are holes in the overflow box halfway down which shoot water to the middle of the tank. Do I need that kind of water flow in the middle of the tank for a FOWLR tank?

Anyone? Please? I'm going to order them soon and would hate to be stuck with it, not using it.

 

[Mouse]

I wouldn't have thought so, but if your planning on converting it into a reef late on i would sereously consider it. These plans were really just me brainstorming online. I dont think i would actually build the above plans because it allows the tank to Syphon empty if one of the closed loops busted. Id still use the same sort of configuration, but id loop the outflow pipes over the top of the tank and include a syphon break. Many people do have setups that could syphon dry, and my problem is some do. If i plan for every eventuality, then ill probably only hit on a new problem, but theres far too many mistakes to make by yourself.