Question on Overflow...

[MattP725]

I was beginning to look into the possibility of purchasing a sump (or making) for my 55g. I don't plan on having the 55 for more than 1 1/2 yrs more so I wanted something that possibly would work on anything up to 120g. Right now I have an allglass and it isn't drilled. I was thinking about getting an OF box instead of attempting to drill this tank and add an overflow (may not even be possible I am not sure if it is tempered). My concern is I hear alot of talk about peoples tank emptying out on them when they loose power. Should this be a concern? I have never lost power in my complex as of yet but I would rather not risk it. Anything else I need to keep in mind?

 

[ohio reefer]

if your wanting to add a sump an over flow box is alo easier and safer than drilling your tank.

if you rworried about power outages take some precautions:
1) add aball valve to the over flow box to regulate flow to the sump

2)buy a sump large enough that can handle the water till it it gets to the point where the siphon is broken

3)add check valves to the pipe(s) that you from the sump to the aquarium. this prevents any back flow siphoning.

i would definately reccomend a sump!!

hth
mark

 

[fishfreek]

My concern is I hear alot of talk about peoples tank emptying out on them when they loose power. Should this be a concern? I have never lost power in my complex as of yet but I would rather not risk it. Anything else I need to keep in mind?

People who say these things never setup their overflow properly in the first place. An overflow will stop running when power goes out once the water level drops to a poitn even with the intank portion of the overflow. This is usually less than an inch below the operating water level of the tank when the power is on. What most folks do is undersize their sump or overfill their sump to a point that the water that does back flow from the overflow cant be held by the sump and thus flows out onto the floor. The way to prevent this is to properly size and properly establish your fill level of the sump and not fill the sump beyond that pont.

For a 55 gal tank I would go for at a minimum a 10gal sump and more realistly a 20 gal sump. To establish your max operating full level you would fill your sump up to max capacity with the return pump powered off. Then fill your main tank to a level even with the top of the inside overflow box. Start the return pump and start the overflow syphon. The water level in the sump will drop to a point and equlize. That point is your max operating full level. If you power off your pump at this point the water should backflow down to the sump and stop when it gets to the top of the tank and not overfill. Never fill the tank beyond the max operating level when doing topoffs and you will do fine.

Other problems folks have is the overflow not starting back up when power is restored. This is most common with the CPR style overflows. These usually have a bleeder tube that they suggest you put a powerhead on to keep air out of the C overflow channel. The issue is if the powerhead does not start back up upon a power outage. Make sur eyou have a good quality powerhead if you go this route. I personally perfer the U tube overflows as they dont suffer from this air issue as much as long as you dont have water flowing thru the U tube at to slow of a rate.

Always match the return flow of your return pump to be slower than the overflows max flow capacity. For example if your overflow has a max capacity of 600GPH then find a pump that does 500-600GPH at the specific head height you are going to have the pump push the water up.

Fore more info on sumps check out our sumps explained article.

 

[fishfreek]

Oh I also forgot to add that on your return lines (those comming from the sump to the tank) a small set of holes hsould be drilled just below the water level in the tank. This way as the water level lowers the reverse syphon is broken on the return lines. If this is not done then water will backflow into your sump till air can find its way into the return lines. Often the return lines are deeper in the water than the overflow and thus several inches of water drains back into the sump.

A one way flap valve can also be added to the return lines but this is not fault proof and could fail. The same holes for the syphon break holes should they fill with coraline or other algaes.

 

[MattP725]

Any recommendations on a good overflow or sump to buy?

 

[fishfreek]

Any U tube style overflow will do fine. I am using an overflow from www.lifereef.com on my 80 gal tank.

I wouldnt recommend getting a retail sump but instead you can make one from an old aqaurium or even a storage tub.

 

[ohio reefer]

go to your lfs and ask if they have anywith a pre filter expect to pay $60 or so