DIY OVerflow?

[rdnelson99]

Not sure if this should go in the DIY section or not. I have a 45 gal tank (36L x 24T x 12W). I had no clue when I went to convert to a SW tank so I listened to the LFS and bought the canister filter. Now I can see where I would be much better off with a sump. Of course, now I have my tank all set up and no holes drilled. I have seen a little bit on overflows and would like to build one. Does anyone have any good plans, details, or explantions of how they work? I am a very handy guy but would rather learn from your mistakes than I would from mine.

 

[rdnelson99]

Bump --------------

 

[scottayy]

Hey..

I'm assuming you mean a hang on back overflow. The concept is pretty simple, really.

There are two boxes, one on the inside of the tank and the other on the back of the tank.

The box on the inside of the tank has teeth or some other form of skimming/protection from creatures at the top of it (sticking out of the water). Water is skimmed through these teeth and into the inside of the box.

There is a siphon tube that connects the inside box to the box on the outside. Once the siphon is started, this tube carries water from the inside box to the outside box.

Usually the outside box has a little compartment to hold water before it spills over to be drained down the tube. This is so the siphon tube can remain completely submerged under water and keep the siphon going.

Then as the water fills the outside overflow box there are a variety of ways you can send it down the drain to your sump. Some use a standing pipe, various pipe mods, some use prefilter foam.

And for a diagram i did a quick google and found this:
How Does a Overflow box work

It has an explanation as well.

 

[rdnelson99]

Thanks Scottayy. Good reading. I have been thinking about this for a few days I kept thinking of overflowing the sump in a power outage but figured that could be handled with a bigger sump. I didn't think of what happens when the siphon breaks yet the sump pump continues to run. That would not be good. Going to have to rethink this one. LOL Wish there were a way to drill the tank while it is up and running with livestock but I don't think that is going to happen. LOL

 

[scottayy]

With proper care you can get it almost flood proof - I hate to use the term flood proof because you don't know what's going to happen.

In the event of a power outage, you need to make sure the sump has enough room to handle the drainage from the tubes and whatever is in the overflow box. Also, drilling a small 1/4" hole in the return lines that return water to the tank from the sump - about a quarter inch under the water line, prevents back-siphoning.

You can test this by doing a mock power outage (just unplug your sump pump or flick the surge protector switch off). Mark where your water line is and see if your sump can handle the drainage of water. The siphon will stop automatically when the power goes out. Then, repeat. Continue to mark the water line in the sump so you know where your MAX fill line is. I did this and then lowered it by about an inch to be sure I never overflow the sump. I marked with a piece of scotch tape on the outside of the sump since it is see through.

Then, if for some reason the siphon breaks without a power outage, make sure you have enough room in your display tank to accommodate what is in the return chamber of your sump. Your biggest problem here if you have enough room in your display tank to handle the water is your pump running dry and burning the motor out.

Here's a good link:
Melevsreef.com | Acrylic Sumps & Refugiums

 

[rdnelson99]

With proper care you can get it almost flood proof - I hate to use the term flood proof because you don't know what's going to happen.

In the event of a power outage, you need to make sure the sump has enough room to handle the drainage from the tubes and whatever is in the overflow box. Also, drilling a small 1/4" hole in the return lines that return water to the tank from the sump - about a quarter inch under the water line, prevents back-siphoning.

You can test this by doing a mock power outage (just unplug your sump pump or flick the surge protector switch off). Mark where your water line is and see if your sump can handle the drainage of water. The siphon will stop automatically when the power goes out. Then, repeat. Continue to mark the water line in the sump so you know where your MAX fill line is. I did this and then lowered it by about an inch to be sure I never overflow the sump. I marked with a piece of scotch tape on the outside of the sump since it is see through.

Then, if for some reason the siphon breaks without a power outage, make sure you have enough room in your display tank to accommodate what is in the return chamber of your sump. Your biggest problem here if you have enough room in your display tank to handle the water is your pump running dry and burning the motor out.

Here's a good link:
Melevsreef.com | Acrylic Sumps & Refugiums

LOL on the "ALMOST" flood proof. Having worked in construction for 30 years I have learned that Murphy was an optimist. I don't know a lot about sumps but watched a video some guy posted on you tube. He put his sump pump near the top of the sump to reduce the amount of water that could pump to the tank. Is that a good idea or should the pump be in the bottom of the sump for better circulation in the sump?