overflow box

[steve r]

i am going to install a 10 gallon sump for my 29g. i have a rainbow quiet one 3000 pump. i plan on using it submersed. the GPH is 780GPH up to a 6 foot head. my head height will be about 4.5 feet. i also plan on putting my SCWD on the return.

which overflow box and size should i get? anything to stay away from? any extras i will need with the overflow box? i have glanced over a few things mentioning an extra PH to maintain siphon during power outages. i

thanks
steve r

 

[fishfreek]

Looks like the pump above will do about 550-575GPH at 4.5' head. Most overflows that use the U tube will be able to flow 600GPH so you should be OK with any standard U tube overflow.

Those that mention a PH to maintan syphon = Stay away from them.

I vote U tube all the way. They are easy to identify because they use a U shaped tube to get the water up and over the side of the tank vs the C channel style.

 

[steve r]

thank you

steve r

 

[steve r]

so stay away from the CPR models and go with something like this?
http://petsolutions.com/product.asp_Q_pn_E_11800209_A_Amiracle+Overflow+Box_E_

any other brands or exact models that anyone likes?

thanks
steve r

 

[XXFirefighter]

I would get a CPR model....
I'd stay away from the UTube.......
Too loud and the CPR are self priming with a PH in your sump if the power goes out... The U tubes are not unless you make the hose stay in them some how...

 

[Brad]

I have a CPR and I'm quite happy with it. It has never failed and in circumstances where I've broken the siphon due to my own foolishness...the powerhead automatically restarted it for me.

I have to think that all siphons can possibly accumulate air in the topmost part of the siphon. Higher flow probably minimizes this. If ever the siphon is allowed to accumulate too much air, it will stop. The powerhead ensures that there is never any air in the siphon.

If I had a C-siphon, I would still put a tube in the top and connect it to a power head to remove air.

 

[fishfreek]

I have never had a U tube lose syphon during a poweroutage.

 

[steve r]

http://www.aquariumadvice.com/download.php?id=9482

i assume this is a u-tube.

is this a higher flow unit because it has two outputs?

steve r

 

[XXFirefighter]

yes but he's got it set up wrong...
The tubes need to flow into the chanber to create a seal. Then it will start a siphon... There's no way how he has it set that you can remove air from the tubes. Both ends of the tube need to be under water.

As for a U Tube never losing siphon with a power failure, never heard of that before. How does the water stay in the tube? If the power goes out and the water level in your tank drops to below normal, and thats normal cause of how you have your returns set up... Then it'll get air. Unless the only way I can see it is if you have one way valves on everything. On the in and out's

Get the CPR WAY more quiet. better looking as well.

 

[steve r]

good info everyone. could you explain the way the PH runs from the sump to the overflow box? how big a PH? does it run all the time?

steve r

 

[Brad]

The photographed dual c-siphon could work, but the grey pipes on the outside-tank side need to be HIGHER than the level of the siphon pipes on the BOTH sides.

The grey pipes can NOT be directly connected to the siphon pipes.

You can't tell how high those grey pipes are, or whether they are connected to the siphons because the foam obscures that point. A picture without the foam would be more helpful to people.

I tend to agree with Firefighter here...that siphon looks like it will break if there is a power failure.

Connecting a PH to the top of the siphon tubes ensures the siphon can restart, even from dry. It doesn't matter where the ph is. It is usually convenient to put the ph in the tank because it is so close. When the ph removes air, it spits it into the tank.....so the alternative is to put the ph in the sump. That should work, but the air line is likely to be longer and there might be a reduction in the suction that the ph produces.

 

[MadManMac]

Actually, a U-tube should not ever lose syphon if both ends of the tube remain under water, and that is how they are designed.The end of the tube in the overflow section is about an inch below the slots so that even when no water is flowing into the box, the tube is under water. As for the drain section, the end of the U-tube is under water below the level of the drain tube, so even when the level gets too low to drain the end of the tube is in the water. As for restarts, when the water starts to enter the overflow box section agian, it creates positive pressure pushing up on the water. As that pressure increases just a little, the syphon starts itself back up and the water level in the drain section gets high enough to start flowing again. So if set up correctly, the U-tube is actaully more reliable since there is no powerhead to fail and physics makes it work. As for the noise, that is usually a function of using tubing that is too small for the amount of water flowing. Larger tubes let water flow faster and quiter. Just my thoughts on the matter - guess which overflow I have?

 

[captivereefs]

The CPR units are good but you just have to make sure the pump is always on. If the pump stops the unit can eventually break its own siphon.

 

[steve r]

still not sure which one. i like the idea of the u-tube not requiring anything more than mother nature to work. they are also way cheaper . i understand the tube needing to be below the slots. this would also seem to keep air out as well

still debating, thanks for the input

wait ! i just came up with the answer! i will just get 65 gallon i have been eyeballing with the built in overflow! what a great idea............................. i wish!

steve r

 

[Brad]

The physics behind a CPR C-siphon and a U-tube siphon are exactly the same. They are both pipes going into overflow chambers on both sides. Both designs restart on their own, without powerhead assistance because of the basic design described in excellent detail by Madman.

...provided they were running before the power failure. To get them going from completely dry, you have to remove all the air from the siphon tube. With a CPR, you have the ph to do it for you. With U-tube, there are lots of ways, but they are all sort of "manual".

So I think the issue is one of reliability and dependability. I think that all siphons have the possibility of accumulating small air bubbles which can collect at the highest point of the siphon. If these bubbles accumulate enough, they will stop the siphon action.

It is possible that the CPR siphons tend to trap more air bubbles than the U-tubes....(something to do with the square shape of the tube vs. a smooth curve, maybe?) Nevertheless, it seems possible to me that a U-tube siphon can accumulate air, just as a CPR can.

...but I sleep better knowing that the CPR/PH combination will always restart the siphon, whether I'm there or not. I don't care if there is air in the siphon or not...It doesn't concern me since I know it will be automatically sucked out.

 

[steve r]

what pump do you use? the air lifter pump or the rio setup. i just bought the CS90 CPR overflow. i guess the 65 gal. reef ready wasnt a possible solution

steve r

 

[captivereefs]

use a rio 800 RVT venturi pump or a maxi jet with the venturi kit.

 

[AndySmithers]

Use a Lifereef U-tube overflow box and fit a Dursoe (the miniature one that is designed to fit in such boxes).

It will NEVER fail, it will ALWAYS re-start faultlessly after a power outage. It need cleaning out about once every visit of Haley's comet (!) and is as quiet as the grave!
Costs a lttle more than others but, hey, what price avoiding a flood and fish/coral deaths, eh?

Just my 2c.

Andy.

 

[BillyZ]

IMO, as long as they are set up properly, they will both function as advertised. They will both be quiet, they will both restart after a power failure. Which one is "Better" is purely a matter of opinion.

IMO, the the CPR adds another avenue of failure. The air tube and PH to collect air bubbles is one more thing that can go wrong. If the airline developes a leak it will then introduce air to your syphon and break it. Or if the PH fails then it can also cause an issue with your syphon. As I said, just opions, so decide which you're more comfortable with and rest assured that either will work fine as long as they are properly set up.

and yes, the pictured overflow will not maintain a syphon. likely even WITH the power on. It is not set up correctly. the ends of the U tube needs to be below the top of the grey tube both inside and outside of the tank.

 

[Brad]

Mine runs a RIO600RVT.

I always thought about this ph as an added level of security, more than an additional liability....food for thought, that one..

I just reconnected this PH to the same power source that drives the automatic replenishment. Now the RIO600RVT only runs during water top-off cycles, (which is about 1/2 the time). It has randomized my tank water flow quite a bit.

The tank seems quite calm when the PH is not running.