Closed Loop System (CLS) Review

Discussion in 'Pumps and Waterflow' started by Jaco Schoeman, 28 Oct 2009.

  1. Jaco Schoeman

    Jaco Schoeman MASA Contributor

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    A lot have been have been mentioned and said about Closed Loop Systems. I have opted to make use of a CLS in my new tank. This thread will hopefully give people who consider waterflow via CLS an in depth understanding of what to and what not to do.

    Tank Specs and features:

    To bring you guy into picture, my tank is 1000x500x500 (this is very important to keep in mind, as this review is based on this size - and bigger sized tanks will be different). The rear wall is lower than the rest of the sides, with an overflow box at the back with two holes for outlet to sump. I had 5 holes drilled for the closed loop piping, that would then be sitting in the corners, and one in the middle right hand. See pic below of right hand side:

    [​IMG]

    One of the biggest pro's to a closed loop is that you have minimal plumbing in the tank, and there is not heat from powerheads etc. Another major advantage is that, if done right, it is completely Nennie safe. Initially this was my aim with the CLS, as I wanted to keep nennies. So what we decided to do is drill bthe bottom with two holes; these would feed my two external pumps. The problam with this however, is that these two suction holes would obviously suck in anything coming too close to it. So, we then built a box on the bottom, and used eggcrate with and mesh to close it op over this box. This would now leave enough space to suck water in - without harming any livestock. See pictures below:

    [​IMG]

    [​IMG]

    Plumbing and pipes:

    There is basically only two options IMO that you can use for the CLS piping. Either white PVC "conduit" piping or blue high pressure piping and bends. Just a quick word on the two.

    PVC "conduit" piping is manufactured for electrical applications, and NOT water flow. For this reason I strongly advice not to use them. Why? Well the two main issues is flow throught the bends. If you take a 90deg bend of white PVC "conduit" piping, and feel the inside, you will feel very sharp corners and not much bend in it. This REALLY affects flow alot. Also, I have found that these "conduit" pipes won't handle the pressure in the long run. Even when sticking it with PVC weld, I personally feel it will give at some stage (that is if you are willing to have about no flow untill such time)

    High Pressure pipe and fittings on the other are, well, just that. Built for high pressure and flow, so you get better flow through it. Also, the actual pipe is thickerm and because it is darker and thicker, no light penetrates so minimal algae will grow inside it (this contrary to PVC Conduit pipe)

    Okey, hopefully now you have decided to spend the money on high pressure piping and fittings, so let's go on...

    Pipe size is also a very important factor. I personally feel that you are wasting your time using 20mm pipe, as this really is just a jet of water, and not suited for main flow in the tank. Another major factor to keep in mind, is to have your suction size into your pump a bigger size pipe than your outlet. I used 32mm pipes for my intake, and a 25mm pipe for the closed loop and outlets. The basic advatage of this is quite simply this - your pump work more effectively with less stress.

    Your next "skip a heartbeat" expense is deciding whether or not to use unions and valves. IMO, it is a must. The simplre reason is having a valve on each outlet helps you controll the individual flow of that specific outlet. Some areas must have strong flow and others less, so this really helps a lot with that. Then using unions is another major advantage. I have not used unions on each outlet, as space did not allow for this. I also did not use unions on my pumps initially - a mistake that almost made me quit over the weekend... But all is sorted and I have put unions both on intake and outlet now, and this makes for easy removal of pumps.

    Here is the basic fittings for the top plumbing on my CLS:

    [​IMG]

    Now some of you wonder why the Mayonaise is in the picture? No, I am not a rep or promoting it... Basically, Mayo helps to clean that sticky glue that remains on the plastic after I have removed the price tags.

    On bends:

    One thing to keep in mind when doing any plumbing where pumps are involved, is that a 90degree bend really puts a lot of strain on your flow. Basically this is because water runs into a solid wall, and then turns 90degrees and has to pick up speed again. The best way to make a "smooth" 90degree is to use two 45's. What happens is water is basically running twice down a 45deg angle (making the 90deg) and thus this doesn't affect flow as much. The actual space it takes up makes it difficult some times, and I could also not use this concept everywhere. But make sure, where you can, that you do use this smoother 90degree bending, as it REALLY helps with water flow a lot. See picture below for the "smooth" 90deg design:

    (also not the overflow box...)
    [​IMG]

    Pumps:

    As mentioned before, the major advantge of using external pumps for flow is that you do not have those butt ugly powerheads in the tank, that is really just an eye sore. Also, you do not have any heat introduced into the tank, and as I have done it, zero hazard for any nennies or livestock. I have used two 5800l/ph @ 4m head pumps on my closed loop system. I wanted to use two 3300litre pumps (but I am so glad I didn't (well get to that...)

    These pumps were then seated below the intake (VERY IMPORTANT) so that it can easily suck with a bit of help from Father Gravity. Pictures shown are still without unions - a price a paid dearly this weekend when I started this baby up and ended with streams of water squirting out everywhere due to bad glue applications ... Also the return piping was not yet connected when I took these photos. I will update this thread with new photos though ;)...

    [​IMG]

    *Note on glueing:

    When you stick these pipes together, I prefer using PVC weld and not silicone. The main reason is that the silicone is under trameandous pressure, and it will not sustain this long term. When you want to stick a connector and pipe with PVC weld, make sure to sandpaper around the area of pipe that will go into the connector, and also the inside of the connector. Then you apply the weld all around it, stick it in and give in one 360deg turn to one side, and a 180deg turn to the other. You will now feel this pipe really tightening. You can also put some weld where the two pieces come together, to make sure there is no leak. Remember though, that once you stick it with PVC weld, it is inseperable, so think carefully and make sure you cut your pipes right.

    Finished product:

    The finished product now consists of five outlets, each on it's own ball valve. I have dropped the rear plumbing down the back to the bottom, and left the front flows higher, and I used a mixture of 45deg and 90deg bends for flow direction. I also allowed for the nozzles to be able to rotate so I could adjust the flow direction. To do this, I took the piece of pipe where the nozzle should be, and sandpapered it heavily. Then I used white plumbers tape and taped it on that spot. Now the nozzle fits tightly over the pipe, and can be moved into any direction without being blown off the pipe by the flow.

    The final product looked like this:

    [​IMG]

    [​IMG]

    [​IMG]

    Does it work?

    Well, to be quite honest I was a bit disappointed by the amount of flow I got from the two pumps. I helped my dad move a 1.2m tank yesterday, and we used one of these pumps to pump the water from his tank into a container. We used a 32mm flexible hose, that was 30meters long and we pumped the water from a room in the house to the trailer (about 15-20meters far) and the pump delivered a full stream of water. But when I connected it to my tank, and two for that matter) I could really see the effect all those bends and T pieces had. The TYPE of flow however was absolutely amazing. I can adjust the nozzle in any direction and get the flow perfect. I am cycling my tank now, and have a piece of LR with long GHA, and this shows me what flow there is. It really is good flow type though.

    Is it worth it compared to powerheads?

    In my honest opinion, I do not think that a CLS like this is effective enough for the only flow in a SPS dominated tank. If you are planning a LPS or soft coral tank, then it would be great. Even for keeping an anemone and adjusting the right flow around it would work, but it really is not strong enought for SPS.

    It also is not at all more cost effective. The two pumps cost me around R1300 each. The plumbing only cost me around R1700 in total. Compared to other flow methods you could spend R3000 on, this really is only for the person who is adament on keeping a fully "safe" system. The wattage of each pumps is also 90W per pump (which is quote low for these type of pumps) so that does not help on electricity usage. This compared to the 9 - 15W usage for powerheads...

    If you would to use bigger pumps, then maybe it would work better, or even if you could somehow replace the 90deg bends with the "smoother" 90deg design that would also help.

    And and all, it was a lot of money spent, that, seeing that I will not be keeping nennies in this tank might have been waste. I hope however that this thread helped a lot of you guys in planning and building yor future CLS systems.

    Thank you
    Jaco
     
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  3. clinton stanford

    clinton stanford

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    wow! very very nice Jaco:thumbup: looking awesome man.very usefull info to...thank you;)
     
  4. butcherman

    butcherman Moderator MASA Contributor

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    so jaco how did you find out mayo is good for removing the sticky stuff? ;) looking good man
     
  5. Jaco Schoeman

    Jaco Schoeman Thread Starter MASA Contributor

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    Thanks guys... I have three toddlers at home - that should answer eveything... ;)

    Stickers on LCD Screens, car windows etc. etc. etc.
     
  6. FransSny

    FransSny

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    WOW Jaco, I am finally seeing the finished product (had a sneek peek guys ;)) Very Nice job and nice info

    Now where is the new pics...I KNOW there's more :whistling:
     
  7. Jaco Schoeman

    Jaco Schoeman Thread Starter MASA Contributor

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    Hehehe Frans thanx... Nah, I'll only send you the finished plumbing photos, but that is the last that you will see for some time to come...;)
     
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  8. shane

    shane

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    Hi Jaco,
    Great build there buddy. I am busy putting together a CLS for my tank. A question I asked a long time back was, is it advisable to drill through the euro bracing for the CLS pipes to go through?
    Cheers
     
  9. Jaak

    Jaak

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    Awesome diy cls Jaco!!
     
  10. JD167

    JD167

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    Excellent post Jaco. Thank you! :thumbup:
     
  11. Jaco Schoeman

    Jaco Schoeman Thread Starter MASA Contributor

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    Hey Shane. Reffer to the first pic. You will see the middle hole being drilled closer to the side and the others driller further "inn" throught the double euro brace.

    Drilling the hole in the bracing there wouldn't do much, as you still have the rest of the bracing on the sides. I would however not do this on a huge tank, and drill it in multiple places. But I am also not sure, as the LFS I bougth from said I could drill anywhere.

    I would imagine that normal cross over bracing might not hold if drilled, but EURO would.;)
     
  12. shane

    shane

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    Thanks Jaco,
    Yes I was planning on drilling through the "longest side" of the euro bracing, on the back glass. The bracing is 100 mm wide and I was planning on drilling 32 mm holes, but I have decided to rather play it safe and go over the top of the bracing. I think it would have looked a lot neater to go through the bracing but for safety sake rather go over.
    Cheers
     
  13. shane

    shane

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    Oh,
    I forgot to mention that my tank also has two cross braces as well.
    Cheers
     
  14. Jaco Schoeman

    Jaco Schoeman Thread Starter MASA Contributor

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    Nah shane, you would be able to drill it. With Cross brasing and Euro, you can really drill it. You will not break it trust me. As long as you space the holes min 30cm apart on the long side.

    If you go over the top, your pipes will stick into the water away from the back panel, that might not look good, and you'll loose space for LR etc. Also, if you thought about using bends to go back to the glass panel, I must remind you of flow loss from bends.

    Go through the bracing, insure the tank with me, and if it pops I will pay you excess... ;)
     
  15. dallasg

    dallasg Moderator MASA Contributor

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    nice thread!
    the reason u lost alot of power is like you said all the elbow and bends, on average you loose 1ft of head per elbow join, and considerable flow, if how ever the pumps were level with the water it would increas alot, in my setup, i found pumps prefered to "suck" against gravity and push down, well i suppose its common sense:p anything is possible with us IT folk
     
  16. Johan van Aardt

    Johan van Aardt I love marines [R.I.P.]

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    just a question on this, i am busy desighning my future nenny cube wich must only host a nenny.

    do your pumps suck out off the tank and just return it in other words if power fails there is really no place for the water to go besides just stay in the pipe?

    how does your overflow to your sump and your return work together with your CLS?
     
  17. Sentari

    Sentari

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    Very cool Jaco!!!! Must say i'm very impressed with the design!
     
  18. leslie hempel

    leslie hempel Moderator MASA Contributor

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    the CLS (Closed loop system) is is exactly that a closed loop pulling water from the display and returning it to an area of your choice or that it is plumbed to go to.. it cannot work with your return pump etc.. the return is a seperate system which must be able to have a syphon break so as not to syphon water out of the DT in the event of a power failure.
     
  19. Jaco Schoeman

    Jaco Schoeman Thread Starter MASA Contributor

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    Yes Johan. Basically what Leslie said. The return pump is a different pump, from the sump.

    If a power failure occurs, the CLS water just stays in it, so not water syphons anywhere.

    The major reason for doing it in the way that water is sucked from the tank and not the sump, is that should you place your CLS pump/s in the sump, you add to the total volume flow through your sump. I currently have a 1800litre pump as a return from the sump. Had I taken the "CLS water" from the sump, I would have added 11600l/h flow through my sump, which is WAAAAAY to fast flow over the DSB, and I recon your overflow pipe wouldn't be able to handle so much water, thus it will overflow...

    The CLS is not connected to ANY form if filtration, only taking water out the tank and putting it back in...

    Hope this makes sense - and good luck with the design... ;)
     
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