Undrilled closed loop (Melev style)

[nekomi]

Hi everyone,

I've been faced with a dilemna over the past couple of days regarding flow in my new reef tank. I have a 37 gal reef, and I've been running 537 gph of flow from my sump return (sump return is the only pump in the system). My sump return pump is a Quiet One 3000.

This gives me about 15x tank turnover, and I'd really like to get it up to 20 - 25x, with random flow instead of direct flow from the one return line. (I'm planning on having a mixed reef with mostly soft and LPS corals, and maybe a couple of hardy SPS such as monti cap.)

In addition, my sump is only 10 gallons, and I'm having a massive microbubble problem in the display. My only guess is that I'm pumping water too fast through the sump, creating the bubbles. So I'd like to downgrade the sump return pump to something slower, and pick up the slack with a new closed loop.

I went to Melev's site and checked out the plans for building an undrilled closed loop. I'm still very ignorant about plumbing, however, so I'm hoping some of you can take a look at my plan and tell me if it will work out:

1. Replace sump return pump with a slower model, Quiet One 1200 (pumping about 214 gph through the sump return instead of 537).

2. Plumb an undrilled closed loop system, based on Melev's design here (replacing the SCWD with an OM 2-way Squirt):

http://www.melevsreef.com/closedloop.html

3. Run the closed loop on my existing Quiet One 3000 pump, pumping an additional 518 gph through the display.

4. Place the intake for the closed loop in my external overflow box. I'm not sure if this will work - I'm concerned that placing the intake in the overflow box will force the overflow to drain too quickly, but I may be totally off on this.

5. Place the two return lines from the closed loop in the main tank.

What do you all think of this? Is this a feasible plan? I'd really appreciate any help... I have to place my order for the OM 2-way Squirt by Friday in order to get into the group buy, so I'm trying to figure out exactly how this will all work. :)

[Cuervo]

As another option...
Take a look in the DIY section at the Maxijet Mods.

I made 2 of them, and they push ALOT of water. It would be alot less expensive and more energy efficient than the CL. You'd have to put up with seeing a powerhead inside your tank though.

[nekomi]

Thanks for the suggestion. :) I would go that route, but I am not willing to have a powerhead in the main tank. I designed the entire system to be very clean, with minimal equipment in the display. My goal is to only have the return lines be visible in the display... I put a lot of cash and effort into making this system as clean as possible. ;) But thanks anyway for the suggestion... I appreciate it! :)

[Nyles]

Just keep in mind the maxi's with the mod are about as big as your fist if not smaller, pretty easy to put in and not be an eye sore. I have CLS and mazi's on my 6 foot long tank, I love the mazis so far. The flow is insane for such a small unit, put one at each end on a timer to alternate and they make great wavemakers.

[seattlerob]

nekomi: I think you're probably right about the intake in the overflow causing the overflow to drain too quickly. I would be hesitant to build the solution that way... Also, if you happen to lose siphon on the overflow, your CL will be running dry, which would probably not be good.

Hopefully you can have your intake in your tank, but be able to hide it behind some rockwork or similar. Don't forget that coralline will cover those pipes given some time.

Good luck with your project. I am currently contemplating doing the same on my 45g.

rob

[nekomi]

Also, if you happen to lose siphon on the overflow, your CL will be running dry, which would probably not be good.

Well actually, it's not a HOB external overflow... there is literally a slot drilled/cut into the back of my aquarium, with an external glass overflow box siliconed onto the back. There is an overflow grill/comb made out of acrylic and siliconed in place to skim the water going into the overflow, with two Durso standpipes in the actual box. I'll take a photo for you later this evening. :)

But in the meantime, thanks for the tips... I'll be back later and respond more thoroughly. :)

[Cuervo]

I think there's a calculator on the home page that tells how much flow you can get through a certain number of inches of overflow.

I'd take a look at that and see if your overflow can handle the volume of your return pump and your CL at the same time.

If it can handle it, then you could stick your suction side of your CL in there. (like you said) You could also change your current return into the suction for the CL, and have the sump return and the CL return both come over the top.

I'd still urge ya to reconsider on the Maxijet, because you get alot more bang for your buck, and they are small enough to conceal fairly easily.

[nekomi]

I think there's a calculator on the home page that tells how much flow you can get through a certain number of inches of overflow.

Thanks for reminding me about that calc! I checked it out just now and my overflow can handle it. It was originally designed to move roughly 700 - 800 gph.

Originally, my plan was to use a more powerful return pump in the sump, but the return chamber drained so quickly that the pump would become exposed. This left me with the flow problem that I'm dealing with currently, because I had to downgrade to a slower pump.

I don't think it was a matter of the drains not keeping up with the flow in this case; in a 10 gal sump, with two sections already partitioned off for bubble trap, skimmer, fuge return and fuge pump, space in my return zone was extremely limited and drained very fast. In all, my return zone was only about 4.5" x 10" x 7", and the pump itself actually took up a good portion of that space. It barely fit, actually!

You could also change your current return into the suction for the CL, and have the sump return and the CL return both come over the top.

That's a good idea... I think I'll look into that, thanks! :)

I'd still urge ya to reconsider on the Maxijet, because you get alot more bang for your buck, and they are small enough to conceal fairly easily.

Thanks... I'll keep that in mind. :)

[nekomi]

By the way, here's some photos that show how the overflow box is put together...

http://www.winds.org/nekomi/overflowbox.jpg

http://www.winds.org/nekomi/overflowbox2.jpg

The tank itself with the black acrylic overflow plate in place, and the return lines (there used to be 2) attached...

http://www.winds.org/nekomi/37g_1.jpg

http://www.winds.org/nekomi/closeup.jpg

And the sump. I didn't worry much about the silicone looking nice. ;)

http://www.winds.org/nekomi/sump5.jpg

Thanks again for all the advice and tips. I really appreciate it! :D

[jstraka1]

If you are going to make a closed loop with the quiet one 3000 use 1" pvc, and I wouldnt mess with the overflow just buy some black pvc pipe (for inside the aquarium) and install a black slip intake strainer. I would make it HOB and put the intake one one side of the tank and the outlet with 3/4 inch locline on the other side. The black pvc will be pretty clean looking. If you cant find black pvc you can always paint it with krylon fusion spraypaint, I guess it is reef safe.

I have made a hob closed loop with a quietone 3000 and 1"pvc rigid and flex pvc and was very happy with the flow, but I now have maxi-mods and I must say that they put out a s**tload more flow, there really is no comparison between the two. I would guess with a tank that size one maxi mod would be much better than the closed loop you are propsing and be much less intrusive, as well as less work, and maintenence.

HTH

[jstraka1]

BTW,

That's a nice looking setup you have there. Keep up the good work!!!