Syphon box vs. built in overflow

[Rick O]

I'm trying to decide between an Oceanic 120 with built in overflows and a 180 with out. LFS is offering me a good deal on an in stock 180 show or I can order the 120RR. I like the idea of the extra size but I'm not too sure about the problems which might be associated with the syphon. What happens if there is a power failure? Will the syphon start back? The built ins take up a lot of space. I need ya'lls opinions. TIA.

Rick

[Doug]

Hi Rick,

I have been using the Amircle U-tube type overflow on my 75g tank for over two years now without any problems. If the power goes out the syphon is kept because the compartment on the outside back drain box and the inside surface skimmer box never loose water. I just setup a new tank using the exact same type of overflow again without any problems. I did not want the large reef ready overflows taking up so much space in my tank either. I have only cleaned the U-Tube in my overflow about 8 times since it was installed on the 75g. The only thing that I could think of that would cause the syphon to break is if something gets into the U-Tube like a snail or fish or if someone pulls the U-tube up/out of the box.

I have also used the CPR hang on overflow but had many problems with it losing syphon. If the flowrate would slow down the overflow would collect a bunch of bubbles and stop working even with the recommended Rio pump attached.

HTH

Doug

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Doug's Reef and Fish Page (http://38.222.244.200/dougw)

[Doug1]

I gotta concur with Doug(no relation) a properly constructed U-tube overflow works fine, but seems limited to about 400ghp with 1" tube and drain fitting, depending on how much water you want to move between tank and sump I figure you will need at least 2 possibly 3 overflows to accomadate the water movement you need.
While they don't take as much space as the corner overflows I think on my next tank I will have 2 holes drilled for appropraite sized bulkhead fittings and use screened elbows to regulate water level, mainly for the volume and ease of setting up. I'm lookin at upgrading to 120 but If I were dealing with a 180 I would use 2x1.5" drains, FWIW

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Reef as though your life depended on it, yours might but the sea's does.........Doug ReefCentral/ReefTank moderator

[Psyduck]

I personally hate my overflow box. Maybe I just dont know how to use it, but I have had more than one tank overflow due to loss of syphon. Also, my fish sometimes have issues and get sucked into the overflow. My father has one witha corner overflow, and he never has problems with it. Every tank after this one will have a corner or built in overflow, forget the box.

[Agu]

I've never had a syphon overflow so maybe my opinion is worthless, but I'm on my second Oceanic predrilled RR and have never had a problem. The idea of losing syphon is something I've never even thought of. With a RR water always runs downhill, Why would you want to fight gravity if it were unnecessary? Sounds to me like the LFS is trying to unload a white elephant on the first available buyer.

[DaveinKY]

I agree with Psyduck, I really dislike my overflow. I've never had a fish issue, but I've had syphon loss more times than I care to remember. The next tank, which will be soon I hope, will have built-in overflows. BTW, I have the CPR type overflow like Doug mentioned.

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Dave

[Larry M]

I've run two tanks for the past two years with hang-on syphon overflows, and never had a problem. The key is to set them up properly to begin with, keep them clean, and run the proper amount of water flow through them. I would never buy a new tank without a corner overflow, though. They are just too slick and remove a lot of the potential problems.

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Larry M

See my tanks at Northern Reef (http://www.reefcentral.com/northernreef/index.htm)

[SaltyDog]

I've had a hang-on overflow for the past year or so and have never had a problem with it and it takes up less space than a corner overflow. It also costs a lot less to just get the hang-on type. My only complaint is taht sometimes the u-tube gets a bubble in it and that reduces the flow but all I have to do is shake the tube back and forth and the bubble works it's way out in seconds. Starting the syphon is extremely easy, just stick a piece of flexible airline hose inside and suck all the air out. I never get a mouth full of water, not even a taste. I have the amiracle brand hang-on FWIW. The built in type looks cool but unless you build that special tubing system to cut down on the noise they are louder. I just put a small cloth over the backside of the overflow and that muffles all the noise. So, why pay more?

[Larry M]

No expert, but IME nothing too complicated about it. Just keep a good flow (over 300 gph) going through it to minimize bubbles in the u-tube, clean the u-tube (in fact I keep a spare on hand so I can swap it out), don't impede the flow at all (no strainers, screens etc--psyduck, your lfs has set you up with a recipe for disaster). Make sure the external box has a divider to preserve the syphon in case of a power outage, test it by shutting down all pumps periodically, make sure the inside box is adjusted to the right height...that's about it for safety purposes, noise is another problem. Everyone has their own trick to reduce that, the towel over the box is a good idea.
http://www.reefcentral.com/northernreef/miscphotos/hooverflow1.jpg

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Larry M

See my tanks at Northern Reef (http://www.reefcentral.com/northernreef/index.htm)

[Rick O]

You guys make this a tough decision. The 120RR has already been ordered and will be in next Friday. The LFS doesn't care which one I take, they are making me a good deal on either. I would go with two of the "U" tube overflow boxes anyway. I already have a Mag 12 which I plan to use in the sump and I think it pumps about 850gph at 4' head. I was just concerned about the reliability of the syphon.

Larry,

I was planning to use a 30g glass sump with baffles similar to your design. I was going to put the last baffle close to the pump so that if the syphon breaks there would not be much water to pump back to the tank, hopefully not enough to overflow the tank. What do you think about this idea?

Rick

[Psyduck]

Ok Larry, what are the secrets of setting up a good overflow box. To stop the gurgling, my LFS put on greated plugs (cone shaped). The problem with these is macro sometimes gets sucked into them and reduces the flow. I have 3 U-tubes doing the syphoning. My only complaint is that with my canopy its hard to access the box to clean and whatnot. Plus its always an adventure to get the syphons going again after tearing down the entire box to clean before the tank overflows. We need a syphon box tips sheet :).

[alde]

I have a siphon box with a U tube. I drilled a hole in the to of the U, epoxied a piece of that hard air line tube to it the put some air line to a powerhead in the tank. The power head is always sucking some water out of the top of the U and with it comes any air. So far it works well. I never see air build up like I did before the mode. You also need a good flow. The faster the water goes the less chance of bubbles building up.

I just wish there were a good way to cut down on the noise.

Al

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He who feared he would not succeed sat still.

[Rick O]

You're the best Larry. I love the pics you're always putting up.

Rick

[Psyduck]

Dont you get a lot of gurggling Larry?

[Rick O]

Psyduck,

A friend of mine has one and cut a piece of acrylic to fit over the outside box and the noise was reduced considerably.

Rick

[Ironreef]

I would tell the LFS that I want the 180g with 2 build in overflows with a good deal or just buy a tank from another one and let them know this. Don't let them bully you or rip you off is possible. If you spent alot of money you should get what you want and be happy. Don't settle for something or you won't be happy.Sounds like you want the 180 but can't get overflows internal? I hate external and will never go back.

[Larry M]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Psyduck:
Dont you get a lot of gurggling Larry?<HR></BLOCKQUOTE>

Yep, they tend to be noisy. You can try sticking a piece of airline part way down the drain line, do the towel trick, some use a ball valve on the syphon line (I don't like this idea) etc etc, but overall they are noiser than corner overflows, IME.



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Larry M

See my tanks at Northern Reef (http://www.reefcentral.com/northernreef/index.htm)

[JSC]

Larry, could you detail the needed divider? Do you have it slightly higher or lower than the drains level or... I am setting up a basement sump soon and am going to be using a syphon box, the one I have currently have has no divider. As a backup I was thinking of having the return pump high in the sump so if the siphon broke I would not have 125 gallons on the living room floor. Thanks in advance Jason

[This message has been edited by JSC (edited 04-30-2000).]

[Steve Richardson]

internal or external... noise can be a problem.

This can be used in either. Works like a dream...its dead silent. I use in my Amiricle overflow.
http://www.reefs.org/ubb/Forum1/HTML/005702.html

-Steve

[Psyduck]

Larry, do you only have one tube there? I use 3 with mine :).

[coralhound]

RickO,
why not buy the 180 and get the back drilled?
This I am SURE of NO ONE has ever said my tank is too big.... :D
food for thought.
CH


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Please BUY captive bred marine life...
My website: Moon Tide Reefs (http://www.qis.net/~ckkuehn)

[Larry M]

JSC--the idea of the divider is to keep the end of the u-tube submerged, and therefore full of water, in case of power interruption. It is fixed into place, not adjustable, about 3" high. I'll see if I can get a better picture of it today.

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Larry M

See my tanks at Northern Reef (http://www.reefcentral.com/northernreef/index.htm)

[Rick O]

Well I decided to go with the 120RR, but the overflows did not have anything to do with my decision. Its just that the 180 was too big for the space in my house where I wanted to put it. It would have partially covered two windows. Also it would have cost a fortune to light and fill with LR. After talking with people that have the hang on boxes I don't think flooding my house would have been a big concern. Larry, I saw the divider in the hang on box but didn't know its purpose until you explained.

Ironreef, I don't know how you got the impression from my post that the LFS was trying to persuade me into buying one over the other.

Rick

[Vins Fins]

Hi Rick,

what i did in my 75 gal tank cost me approx 15$. I used a bread box, just cut slits in it
like the syphon boxes are.used aluminum strips to hang it inside my tank. then i plumed pvc
3/4" from the box directly to the sump. no box on the back of the tank. I installed a b-valve in return and supply back to the tank. for water leveling control i drilled
a 1/8" hole in the u tube where i wanted the water level to be in the tank. seems to work great for me,no noise, i'm not even sure what everyone means about the gurgling.if the water goes to low then you will start to hear air wisping in to the u tube. this will level out and quiet right down. also on you're pump,make a u-tube in the sump approx 1 to 2"
from the top of the sump, this will create a vortex if the water gets to low and will also
act as a leveling device. it's also a great way to add oxgen to the tank.

http://home.twcny.rr.com/vguarno/

Vinny

[Ironreef]

I thought they were only selling whats in stock? You can buy any tank with internal overflows from any LFS by me.Having Both kinds of overflows in 2 different tanks there is more of a chance with floods with the hangon box. Once you have internal you will never want a hang on.Hang ons do make alot more noise you can build silencers for internals.Anyway a 120 is still a good tank.

[Rinaldi]

Rick - Option #3 (W/180)

Doug1 and Coralhound mentioned this one and I am always surprised its not more popular. I had my 75g ($100) tank drilled in two places on the back wall near the top at either end and I installed two bulkheads. (You can also do just one, but two is safer) Then get two PVC 90 elbows from the bulkhead to the water level surface. Use vinyl tubing from the bulkheads to the sump and you get no noise, lowest cost, and great surface skimming with an ability to rotate the PVC elbows and regulate the level of water in your tank. IMO it beats an overflow box in function, price, and safety/reliability and is alot cheaper than the expensive built in overflow tanks.

[Rick O]

Rinaldi,

I wouldn't mind having a tank drilled like you mentioned. In fact, I've studied the way the LFS has their tanks set up with the holes drilled in the back. Problem is no one wants to drill it and take the responsibility for cracking it. LFS drills their own tanks and it took some convincing to get him to agree to drill an old glass tank for my sump, even though I told him I wouldn't hold him responsible for it. I still have the issue of the tank partially covering two windows so the wife has pretty much made an executive decision.

Rick

[Ironreef]

Haha my wife shut down my 180g then my 150g had to settle for a puny 120g also. I guess I better put my apron on and go cook dinner before she gets home. It still beats my 55g.And I wont go broke maintaining it.