Woo Hoo 2000 GPH on my 75

[Jeff Hood]

Just finished the install of my 1000 GPH closed loop system for my 75 gallon tank. This is a future SPS system.
That gives me a total of 2000 GPH or roughly 23 turnovers per hour. The current does not seem that much but its nice to see the corals move for a change and open up more fully.

I run one Little Giant 3mdqxsc through a 3/4 inch sea swirl in a closed loope with three one inch screened intakes. The second is another 3mdqxsc which is split between a spray bar behind the live rock, 3/4 sea swirl and a stationary nozzle that runs the sump.
what is nice too is I don't run the entire volume through the sump. No micro bubbles and also no darn Powerheads to mess with or look at. I don't have a drilled tank but the design works very well and is very simple to make.

Jeff

 

[Anonymous]

Please Post some pics! I am in the middle of plumbing my 100 and am looking for ideas.

B

 

[EEreefer]

Sorry but that description of a closed loop system is too complicated and too narrow. A closed loop system basically means that there is no sump or overflow involved in the loop. The pumps inlet is plumbed directly to the tank via a bulkhead/strainer setup or some such and the pumps outlet is plumbed, once again, directly back into the tank. Putting the pump above the tank is a real nightmare, IMO, and not a part of the description of a closed loop system. Closed loops are used to increase tank flow rates and "usually" have nothing to do with filtration schemes and such. Also, since a closed loop doesn't include an overflow there is pretty much no limit to the size pump you can use. JMO.

 

[myreef]

I agree with EEReefer about a closed loop not being part of any filtration in the tank. It is just a way to move a lot of water in your tank without powerheads. However, a closed loop with the pump above the tank does not have to be a nightmare. I have to running with the pumps above the tank. If you want detailed descriptions with how I did it, got my website then the DIY section. It is complete with pictures and description of how I did my closed loop. Again, my pumps are above the water line to save space in my stand and since I have an acrylic tank it was easy to do. i also show an easy way to prime the pipes. With all that being said, if I could I would have put the pumps underneath in my stand.

With my 2 closed loops, I am now moving 22-34 times my tank volume, depending on the timers. HTH...

 

[2poor2reef]

I think closed loops are the best thing for sps tanks since protein skimmers. I run very small sps tanks (15g) and very high water movement, like one tank turn per minute. I have never been able to move that kind of water through my sump without returning bubbles to the tank. But with a closed loop I run only 30% of the volume through the sump and can baffle it out.

 

[Psyduck]

Interesting idea this closed loop thing. I run a Little Giant as my return pump, and I get pretty good flow, but only have 2 return lines, so not all areas of the tank are getting good circulation. I guess It would be possible to put another pump below the tank and plumb it in this way, to just suck water from the tank down and then back into the tank in a variety of ways (spray bar, more return lines). I agree, much better than 10 powerheads plugged in

.

 

[Jeff Hood]

You don't need the pump to be above the tank. Make a PVC overflow that goes down about 6 inches into the tank. I made my overflow with three one inch strainers to reduce the pressure on any one strainer to prevent sucking in some small helpless shrimp. tie that into your pump. The return line will go back up to your tank to what ever type of return nozzle you want. I use a 3/4 inch sea swirl.
Since the output and input of the pump is in the same place there is no risk of running dry or siphening out your water. Its foolproof unless you have a leak at the pump itself.

You can order the one inch strainers that screw into standard pvc fittings from pet warehouse.

Jeff

 

[Jeff Hood]

the pump outputs I mention at the bottom of the pic is not my outputs but was an example for another system I was helping with.

Jeff

 

[myreef]

Nope, you don't need the pump above the tank at all. In fact, it is easier to do it below. Thought we said that

hehe....the reason I did it that way was because of space below in my stand. I have skimmer, reactor, CO2 tank, etc, etc in my stand. So I had no more room, therefore I put it on the top.
Like Jeff said, all you need to do is have a bulkhead or a way to get the water directly to the loop pump, then back into the tank. No fuss, no muss!

 

[lawndoctor]

Could you use an overflow box for the input side of the closed loop, or would it be bad because it would recirculate the surface water?

 

[EEreefer]

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by lawndoctor:
<STRONG>Could you use an overflow box for the input side of the closed loop, or would it be bad because it would recirculate the surface water?</STRONG><HR></BLOCKQUOTE>

The point of the closed loop is to maximize the flow without a possible limiting factor, such as an overflow box. That being said you could do it but it's no longer "closed" as such. Skimming the surface water is never a bad thing IMO.

 

[Jeff Hood]

I would definatly NOT use a surface skimming overflow box for your Closed loop. It will suck in air along with the water and cause massive microbubbles.
You want the intake pipe with a screen well below the water level so no air gets sucked in. Use your sump intake for skimming the surface so all of that stuff goes to your skimmer.

Jeff

 

[Emmitt]

OK. I got a question. How do you guys with the 20 to 24x tank turnovers keep your sand on the bottom of the tank?

Seriously.

 

[Jeff Hood]

Most of the current is at the top of the tank in my setup. There is a lot of current down at the bottom but not enough to disturb it. I also have larger chunks of coral rubble down there also.

Jeff

 

[kangol99]

What is a closed loop system?
Is there any pics or info on how to create a closed loop system? I've been hearing about this for a while now but really haven't seen any pics.

 

[Reef55]

I forget the link to pics of it, but basically for a closed system you put the pump above the tank. Attach an intake tube that extend down into the tank, and then the output tube runs to wherever you want, then attaches to a seaswirl or just an elbow. Getting them primed with water is a little tricky, but once the entire tube is filled with water, and both the intake and output tubes are completely submerged, it won't lose its siphon. It gives you the benefit of a high flow rate (zero head), and no pumps are in the tank. Just the intake strainer and the output. It helps to build the hood tall for this, or have the tank off the wall a little and sit the pumps just behind the tank on a small platform.

 

[Bubafat]

I just set up a closed loop system on my new 37 gallon. My LFS employee thought I was on crack when I asked for a 37 drilled for 6 1" bulkheads. 1 for to sump, 1 from sump, and 4 for a closed loop. I have a Mak 4 on the closed loop. I also figured out a way of reversing the flow using T's and ball valves so I can have the flow going right to left one day, and left to right the other. It's kinda cool.

Total, I have 1950 gph on my 37 which equivilates to 53 times per hour.

Buba

 

[2poor2reef]

Emmitt, I don't think you have any problems at 20 or 25 turns per hour keeping sand in place unless your outputs are unusually concentrated and directed toward your bed or your bed is primarily silt. But I run my small sps tank above 60 turns and I run bare bottom becauser I can't keep any sand on the bottom with movement like that, even though 100% of the flow is either bounced off glass via sea swirls with flared outputs or via spray bar.

I just run my dsb in a connected refugium. Nothing wrong with bare bottoms. That's old school berlin method ya know.

 

[myreef]

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by Bubafat:
<STRONG>I also figured out a way of reversing the flow using T's and ball valves so I can have the flow going right to left one day, and left to right the other. It's kinda cool.

Buba</STRONG><HR></BLOCKQUOTE>
Hey Buba....are you turning the ball valve manually or is it an electric solenoid valve?

 

[Anonymous]

How well do the fish cope with it?

-Greg