Overflow box setup

Although the hole vent is typically very small, a considerable amount of air is drawn through it. The water and air mixture that travels through the pipe down into the sump mixes together vigorously.

The bubbly water dumps into the sump. When the water exits down in the sump, even more bubbles are created. The bursting bubbles result in salt spray — and salt creep on the surrounding surfaces. One shortfall of these vented drains is that they are only quiet when at the low end of their flow capacity. If you could look top down into the pipe, you would still see air in the middle of it.

Once you increase the flow of water past this point, the drain begins to draw in a considerable amount of air. The air and water mixture becomes very turbulent inside the pipe. It starts to make more noise as flow is increased. For this reason, large plumbing diameters 1. This is usually not an option on many smaller tanks. They are still very common despite the fact that they have no safety backup and are typically loud.

Many people convert these types of single drain systems into siphon valve based overflow methods like the Herbie 2 pipe or Bean 3 pipe design to get more capacity and take advantage of the other benefits of a siphon system. Siphons are silent when running and have much more capacity and safety measures than a Durso or vented drain.

They also produce no bubbles. Any time you run a siphon pipe you must use an secondary emergency pipe. You are purposely constricting the flow of the drain with a siphon valve, so the emergency line must be present for a safe system.

A two pipe design, consisting of a valve-controlled siphon drain and an emergency line next to it. The siphon pipe has a valve on it — allowing for it to be balanced against the rate of flow from the return pump. This creates a consistent resting water level in the overflow. With the correct height of the standpipes and a submerged outlet, the siphon will reliably re-start when the return pump loses power, and then starts pumping again.

No manual adjustment is needed. Running a trickle down the E-drain is controversial but nonetheless widely practiced. The Herbie method is a common way to quiet down an existing overflow box with 2 standpipes present. Many times an existing return line is converted into a drain line, then the return is plumbed over the back of the aquarium.

For more info Check out this page: Herbie Overflow Guide. A 3 drain overflow is often referred to as a Bean Overflow. It is widely considered the best overflow method. The original Bean design refers to a specific implementation — a coast to coast overflow with a relatively shallow box containing the pipes. The Bean design uses the same valve-controlled siphon drain as the Herbie setup.

That is where the similarities end. The second pipe acts very similar to a Durso because it is vented with an air hole — preventing that pipe from being a siphon and making it quiet. Small variations in flow are taken up by the open channel drain. By adding a third pipe — a dry emergency drain — safety is increased. The system also gains capacity because unlike the Herbie, the open channel can take in more water than just a trickle.

Because a dry emergency line is always there, there is an extra safety measure in place. For this reason it is common to see siphon inlets with no strainer a must with a Herbie and toothless overflow weirs being used with the Bean system. In the last few years there have been a few companies making external overflow boxes out of acrylic that use a 3 standpipe overflow design. They can be installed by drilling a few holes in the tank.

An external box housing the pipes is connected to a smaller overflow weir box inside of the tank with bulkheads. In their own category, these were created in order to get water down to the sump from tank without having to drill it. They utilize a siphon to pull water up and over the lip of the tank and hang on the trim. Overflow boxes are fundamentally flawed in that they rely on a siphon with no backup. The pump runs 24 hours a day and the water needs somewhere to go. Some models will employ a pump to constantly provide negative pressure to the pipe that carries the water.

The idea is it will quickly restart a siphon when power to the return pump is stopped and then re-started. Unfortunately these pumps are often in the 20 dollar range — not having your tank overflow is too big of a responsibility to put in the hands of a cheap pump. Time 10 seconds from once the flow has established and watch and see how much water flows out. The gallons per second will tell you exactly what type of pump to buy. If you are unable to perform this test, buy a pump with a variable speed switch to manipulate the flow to match the outflow.

With the correct size pump, start the gravity outflow and plug your pump in. Watch your sump line carefully to make sure it isn't creeping up or sinking too low. You may have to manipulate your pump setting to match the flow of gravity. Check your sump level a few times over the next 48 hours and make adjustments as necessary. As with all other biomedia, it will take approximately four to six weeks for the media to be fully "cycled. When done correctly, sumps can be a great tool for your aquarium.

They can increase your filtration capacity, increase your total water volume for improved water quality, and create a better environment for your fish. Actively scan device characteristics for identification.

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Measure content performance. Develop and improve products. List of Partners vendors. A baffle in the sump is basically the exact same thing as the overflow is in your tank. Each has their upsides and their downsides. Generally speaking most folks are going to want an internal overflow if at all possible.

The advantages and disadvantages of each are:. The construction of an internal overflow is very simple, they are basically a 4 or 5 sided box. The 4 sided boxes are open on the top and the back. The back is secured with silicone directly to the back of the tank surrounding the drain hole. The 5 sided overflow boxes are identical except that there is a back on the overflow box itself. With the 5 sided boxes you do not need to secure the box to the tank with silicone; however you need to add an additional gasket on the bulkhead between the overflow box and the glass to prevent water from seeping between the box and glass and then out the bulkhead hole.

An internal overflow box is more desirable then an external in almost every way. They are less expensive, offer flexibility for much more customized or complex plumbing, etc. The only catch is that it requires a hole in the glass. Instead they suck water over the side of the tank by means of a siphon. They do their job and are quiet effective. As your return pump continues to pump water up to the tank and it has nowhere to drain, eventually it will overflow.

Modern hang on back overflows like the CPR aquatics overflows include a small pump that draws out any small amounts of air that may enter the siphon and help keep it primed. This process is a lot more straightforward. When it comes to sizing an overflow, you just need one that is large enough to handle the capacity of the return pump you plan to get. Fine, get an overflow and make sure that your return pump is smaller than the overflow.

As a rule of thumb I usually take my tanks size, multiply by 10 and then round up to the next largest overflow. The CS90 overflow from CPR is rated for gph and is the closest overflow in size that exceeds gph. Be the first to know about the sales, specials, new products, the latest BRSTV episodes and win free prizes! The store will not work correctly in the case when cookies are disabled. Close Call Email. Shop By Categories. Home Choosing an Aquarium Overflow.

How an Aquarium overflow works and how to choose the right overflow.