What's wrong with this idea?

[luvabunny]

I'm not having any luck finding a pre-made overflow that will fit in the available space on my tank....but...

I have an extra "U" with a guard (basically from a broken HOB filter). Why can't I simply attach a hose to the bottom of it, start the siphon and use it to fill the sump? I could add a twist knob to regulate the amount of water if it seemed to be too much. I'm thinking if I drill an airhole at basically the same place an overflow would stop, that would save me in case of a power outage. I would need to fabricate a sump level, for just such a situation, to turn off my pump. That would be a little harder, but less necessary in my opinion. (I would prefer a ruined pump to a drained tank and water in my floor!)

So, since I'm sure this has been thought of and discarded before, why don't people do it? Basically the same set up runs my canister filter.

 

[iamwrasseman]

it will not work at all . the water flow would have to be perfectly matched and that is not possible at all . it could be adjusted to work for a minute or two ,three or four but eventually it would not match and then your floor would be quite wet . pump flow .algae build up , and just plain luck wont let you do this . goggle "glass holes" and look at what they have as you can get a 6"x6" overflow that only protrudes 3" from the back of your tank . if that wont work you can even install it on the side if need be . they are simple and also easy to install . all you need is a drill and lower your water four inches for a few minutes to drill your hole .

 

[luvabunny]

A side installation won't work as I have to keep the glass lids to keep the fish in, and drilling is out of the question, not an option, not even a consideration.

I just don't understand how the U tube without the overflow boxes won't work as well as the exact same U tube with the overflow boxes. The way I understand it, the overflow box inside the tank is just to keep fish, etc out of the tube. To be honest, I'm really not sure what the overflow box outside of the tank is supposed to do besides create noise.

The U tube is exactly the same size, so it seems it should siphon exactly the same amount of water, whether it goes thru the boxes or not.

What am I missing here?

 

[chaderic26]

I just don't understand how the U tube without the overflow boxes won't work as well as the exact same U tube with the overflow boxes.

It's magic.

 

[Tek]

I have a new continous flow overflow box you may want to look at. It is rated for 1200-1500gph, but may be a bit larger then what you are looking for. I can get dimensions tonight.

 

[iamwrasseman]

wait, you are using a u tube from one tank to the next side by side ?

 

[cody6766]

The HOB overflows use the siphon to feed the other side of overflow box, not the sump.Water is pushed from the sump to the tank via the return pump. The tank can only hold so much before overflowing into the front of the overflow box. When it does the water is siphoned to the back side of the box (out of the tank) and then drains via gravity (like a sink drain, not a siphon) down to the sump. The siphon is isolated to the overflow box, not the sump/tank.

If you leave it siphoning from the tank to the sump you will eventually run into an imbalance between the speed the siphon drains and the speed the return pump can fill the tank. Either the sump will run dry, something will overflow or the siphon end in the tank will run dry. I made this mistake early on too and was baffled. I got it dialed in to be reliable for about 6hrs, but that was the best. You need a HOB box or an internal overflow to do it properly

 

[luvabunny]

Cody, thank you. I do understand now. The magic line was "The siphon is isolated to the overflow box, not the sump/tank." So the back overflow box is used for something more than just making noise.
I knew it was too simple of an idea for everyone not to do it if it would work. I just couldn't explain to myself why it wouldn't.

Joseph, I think you're right, it'll probably be much larger than needed. My pump is only rated at 700gph with no head pressure.

I think I'm going to be checking around online at a couple of places. Had I known this was going to be such a nightmare, I would have kept the one that originally came with the tank....

 

[lauremf2002]

I have seen pvc only overflows in the DIY forum, so I know its possible. Also, I think some people are confused and think you intend to use the pump in you hob filter with the U. You are intending to siphon only though, correct?

On another note, it would be fairly easy to build an acrylic overflow to fit your dimensions. Acrylic is easy to cut with just a jewelers saw (the little hand held kind). I have one if you would like to borrow it. Put together two boxes, then just use flexible tubing for your siphon. I think I could make one for you if you are not comfortable with DIY projects as long as you provided the materials. i.e. some acrylic, acrylic glue, flexible tubing... say 2" diameter, a bulkhead, and two plastic bolts to make the box height inside your tank adjustable. Also, I would strongly suggest a lifter pump. Like the kinds they use for dosing and a little airline hose to keep air bubbles inside the tubes from breaking siphon. Just a thought. Let me know if you are interested!

 

[lauremf2002]

Disregard my whole first paragraph. Cody hadnt posted when I wrote all that and he sounds like he knows what he's talking about. Ive seen pvc only overflows on the DIY forum, but dont personally know how or if they work. lol I do know how the box kind works though so I can still help with that if you want.

 

[mikencarol]

:dance::dance::dance:...youall makin me want to sing and dance...da foot bone connect to da ankle bone..da ankle bone connect to da shin bone...da shin bone connect to da knee bone..................and on and on...April,Regal Plastice has a small plastic cutter for about 3 bucks and every kind of cement you can imagine...and cheap scraps of any size and color....

 

[luvabunny]

Yup, sounds like a call and a trip to Regal Plastic may be in order for tomorrow morning, if they're open.
Seems like I've checked before and they keep bankers hours....or at least the exact same hours I do.
I'll give 'em a ring in the morning and see what I can find out.
Who would have thought a stupid little plastic box would be this difficult to find?

...Mike....stop sniffin that cement....!

 

[Tek]

The GPH rating only pertains to the max flow it can handle. It is new and I also have a new lifter pump to go with it.

 

[EllieSuz]

In my opinion, the best overflow set-up is made by LifeReef. Google them, as they will be happy to make you a custom box that fits your requirements.

 

[luvabunny]

Yup, called Regal Plastics - open M-F 8:00-4:30.
Know when I work? M-F 8:00-5:00. Too far away for there to be any chance of going during lunch.

Joseph - sent you a PM.

For everyone else - the mag 7 is up for sale - $50.00.

Gonna take a different direction for a frag tank.