tank idea

[danimal1211]

Hey everyone, I have an idea for a tank and just wanted some feedback on wether you all see any problems with my design or not. the whole idea is to create a tank with no visible plumbing in the display. I'm gonna do a closed loop through the bottom of the tank under the rocks. The overflow will be external, and the tricky part is the sump return. Instead of the return line actually going into the tank, I thought about having it go into a second external overflow that has holes drilled in the back panel of the tank. I spent about an hour drawing it up on google sketch so i'll load a couple snapshots.

 

[danimal1211]

 

[kcress]

It would be more efficient to separate them on both ends as you are likely to have some percentage of return immediately recycle back to the overflow as designed.

 

[coralfragger101]

I think your biggest problem will end up being getting the right amount of flow to all areas of the tank after aquascaping. I have a closed loop under the sand bed as well as an external overflow box. I figured I could deal with the return lines being visable and they enter the tank over the back side. Even running the CL with a dart (3600 gph), I ended up putting 2 modded maxi-jets into the tank for additional flow. This is on a 150 gal high tank.

 

[danimal1211]

Good point Kcress. I could put the second box on the other side. the top holes are just a precaution if something happens where the overflow loses siphon and the sump return is still running.
coralfragger, I haven't heard of people having flow issues with a closed loop b4, but 3600gph on a 150 seems kinda low. The sump was going to be as low flow as possible, just matching it to the skimmer's output. I'm also planning a more open aquascaping with less live rock and bare bottom.

 

[danimal1211]

http://reefcentral.com/gallery/data/500/165991tank_pic_3-med.png

http://reefcentral.com/gallery/data/500/165991tank_pic_3-med.png

I moved the second box to the other side. the holes in the top as I said are only there in the event something happens with the overflow. They are placed 3/4" from the rim while the overflow level is 1" from the rim.

 

[danimal1211]

 

[markviiisvt4]

The only thing I see right away is you might want to bring your return all the way up then turn it down with some street 90's. The two reasons being that water blasting straight up like that could cause a lot of salt creep, or splash water out. The other reason is if you had a power outage your tanks gonna drain all the way down to the hight of your return line. Other then that i think it's a great idea.

 

[danimal1211]

Yeah i just don't know how to draw actual plumbing on google sketch. that would be pretty funny though to have a fountain springing out the back of your tank though :lol:

 

[kcress]

Those lower holes would be a disaster alright, as soon as the power failed. So yeah, you need to the return to go way up then have a 180 on the top so as the water level siphons back down the return on a power outage the outlet is uncovered quickly. I'm starting to think just a high bulkhead or over the side nozzle is way better. That would represent a single 90 instead of two 90s and all water momentum 'wasted' in the return box.

 

[danimal1211]

the return pipe would actually be much higher than in the picture, most just below the rim (its a little decieving because I cant draw the plumbing corectly), and then have 2 90 degree elbows so that the water is aimed at the bottom of the box.

 

[hebygb]

I dont know what size tank this is, but you may as well consider putting a wider overflow in, maybe even coast to coast. Maybe wide overflow in the middle, two returns on the ends. Additionally, I would cap the return box (perhaps using a gasket and wingnuts) to assure that the water exits the return chamber into the tank and not over the top... The removable top would be for maintenance.

 

[Discustopia]

How about this instead...
I took a shot of my tank before it was full of LR so you can actually see the plumbing. DEAD SILENT - when the return pump is set to the approprate speed you literally have to put your ear up to the overflow to hear it. Now that it's finished the rocks cover all the plumbing. Closed loop strainers are the black cylinders along the back of the tank. Also - to limit the # of holes the returns "T" and are buried below sand.( a tough trick but possible if your'e good with glue and a saw - std t"s are too tall)

from the end

Strainer

overflow ( drain holes are on the main pipe just below the rim)

 

[Schplitter]

Discustopia: I hope your power never hoes out!!! If I'm looking at this correctly your whole tank will drain to the sump and dump the rest of the water onto your floow if you power does go out!! I hope I'm wrong.

 

[kcress]

Very nice Discustopia! Nice and clean.

Schplitter that strainer is to his closed loop NOT his sump.

Discustopia; That 45 is one of the returns?
Do I see three of your stand pipes?

Am I correct in that the central pipe the 'cap' goes on is riddled with holes just out of sight?

 

[danimal1211]

nice tank can you show an updated pic with all the live rock in place? you said the CL returns are under the sand, but where are your sump returns. The closed loop i was planning would have the strainer in the back behind the rocks with the returns under the rocks pointing in different directions. I'm probably gonna use an OM super squirt or even 4way.

As for the sump return, part of the reason I want to try this design is to get the return water from the sump low in the tank instead of at or near the surface without worrying about reverse siphoning, yet keeping the plumbing out of sight. I'm still at least a month away from being able to build it, and i'd like to make a scale model just to make sure it works as planned. The main thing I'm concerned with is that once the water leaves the return pipe theres no pressure forcing it out of the bottom holes, in theory the water would be sucked out into the display as water falls in the overflow.

 

[Discustopia]

Found this thread back - lost it and never replied to these questions.

Must have been late when I posted the first time - the Closed Loop is the strainer and the 45's, don't know why I added the strainer pic in the mix. as it confuses the overflow issue

Actually when the pumps shut off the tank only drains 5 gallons or less
(10 gallons per inch, 240G tank, 24" high).
FTS

FTS 8months later

closer shot with grating around overflow

reverse siphoning is not an issue, return pipe sits just below surface and breaks siphon just as water level drops to top of overflow.

 

[NanoReefWanabe]

<a href=showthread.php?s=&postid=12888866#post12888866 target=_blank>Originally posted</a> by danimal1211

to me this looks like a maintenance nightmare...

you are going to have to clean those little holes at the top of your return chamber daily...cause any obtructions will cause the tank to over flow, heaven forbid a couple snails make there way up there and park over the holes..

the holes in the bottom wont do any good i dont think, as the water pressure in the tank would likely exceed the incoming return pressure, therefor water would not be coming out the bottom holes at all...

if you can handle a bunch of little holes in the return box why not just add a couple 1/2" bulkheads and build a return manifold at the back of your tank, you dont need to add fitting to them just open holes...

i would use the proposed return chamber for a wavemaker and do over the top or through the back returns...

i also second the notion for a much larger overflow box on the back...the more surface you skim the more nasties you get out...the thinner the weir height the better it is...(if the water flowing into your over flow box is doing so at about 3/4" it is far less effective then if it were only 1/8" you want to skim the film off the top of the tank not the top half inch of the tank...) depth of tooth doesnt effect this...it will be determined by the flow, which will dictate the size of weir required to skim at a certain depth....

other then that hidden closed loop sounds nice...(possibly catastrophic, but nice)

best of luck i will watch for you build...