What Size Septic Tank Do I Need?

Installing the right size septic tank is crucial for both having a healthy environment and preserving the wastewater until disposing outside the property.

But determining the right size septic tank isn’t a simple task as it needs to go through plenty of considerations.

So if you are wondering what size septic tank I need and want to handle it efficiently, keep reading on.

In this article, we have mentioned all the related yet essential information and several methods to determine the right size septic tank along with recommendations. 

Know The Basic First

Why Septic Tank Sizes Are Important

The septic tank is the initial stop for the whole water that you release from the home’s showers, toilets, kitchen, and laundry.

Water stays in the septic tank for up to 24 hours with the tank serving (the places where solids are set apart from the liquid). 

This retention period is vital to separate the solids from liquids. Though the Bacteria presence in the tank breaks the solids down, the size of the tank greatly affects the separating and waste braking system. 

Let’s understand the consequences of making too large and small septic tanks so you can realize the importance of the right size. 

Too Small Septic Tank

If you make a too small septic tank than your needs, it won’t handle the volume of water coming from your house.

This will bring various irritating issues like flooding, foul odors, and blockage. 

Despite this, the most prevalent effect it will bring is that the emerging pressure will discharge the water before it is purified efficiently. 

It means that the solid waste in the tank won’t break down adequately and collect the waste faster, resulting in cause blockage and overflows.

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Too Large Septic Tank

Many homeowners don’t want to compromise on the cost and consider too big a septic tank than needs.

But will it be wise to make a too big septic tank? No. A too large septic tank won’t run properly without getting the right amount of wastewater. 

Despite this, a too large septic tank won’t get the sufficient collection required to produce bacteria to break down the solid waste.

However, a larger septic tank is preferable for some special reasons such as:

• It will hold the extra volume during parties or after coming long-term quests.
• It will eliminate the need of installing a new septic tank after increasing the family or enlarging the size of the home.

Local Government Regulations

The local government regulations for installing a septic tank vary depending on the certain area of the US.

The reason is that the water features and soil geographies are largely changed by state or even somewhere by a few miles.

That’s why it’s recommended to check the local government regulations to determine the right spot and size to install your septic tank. 

For example, lake country Florida has their own regulations for tank size and efficiency.

If you don’t fulfill their requirements, you won’t get permission to install the tank.

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Suitability Of The Ground Geology

The type of underground soil has a vast effect on the effectiveness of the system and the size of the septic tank. 

This factor is also linked to the local government regulations and the department of health. 

In this case, you’ll need a certified professional to perform a certain test on the proposed installation area to select the right place for installing the septic tank.

Among the tests, the most common one is a soil percolation evaluation which is known as the perc test.

This test will find out the viability of the underground soil and whether it can handle and filter the effluent of the septic tank or not.

And you should schedule all these local ground geology tests through a contractor.

But if you want to install the tank yourself, you have to contact the local oversight department so they can perform perc tests or ground area evaluation.

The analysis of the result will decide whether your desired place is acceptable or not and the size of tank you’ll require.

The Specific Septic System Type

You can choose from 7 different types of septic tank systems. Among these types, concrete septic tanks are used commonly but they require expensive and heavy equipment.

Despite this, plastic and fiberglass septic tanks are lightweight, making them suitable for remote areas. 

Overall, the conventional and Anaerobic System is preferable and it is used commonly too. the other types are:

• Pressure System
• Aerobic System
• Mound System
• Recirculating Sand or Gravel Filter System
• Above Ground Septic System
• Bottomless Sand Filter System

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Different Types of Septic Tanks Suitable for Various Needs

Concrete Septic Tanks

Concrete tanks are heavy and strong. They last a long time. But installing them takes effort. Here’s what to know:

• Pick the right size. Big homes need bigger tanks.
• Prepare the ground. Dig a hole that fits the tank.
• Install carefully. Use machines, as they’re heavy.
• Check for cracks. Even small ones can be a problem.
• Maintain regularly. Clean out the sludge every few years.

Fiberglass Septic Tanks

Fiberglass tanks are light. They don’t crack easily. Rust isn’t an issue. Here’s how to pick and use one:

• Decide on capacity. Think about the number of people in your home.
• Dig the hole. Fiberglass tanks need a snug fit.
• Set the tank. You won’t need big machines for this.
• Fill carefully. Avoid sudden or large amounts of waste.
• Inspect yearly. Make sure there’s no damage.

Plastic (or Polyethylene) Septic Tanks

Plastic tanks are popular. They’re easy to handle and install. They resist rust and rot. Here’s a simple guide:

• Choose the right model. Check the material and design.
• Prepare the site. Make sure the ground is flat.
• Lower the tank. Some friends can help with this.
• Connect the pipes. Follow the tank’s instructions.
• Monitor the waste levels. Clean the tank when needed.

Steel Septic Tanks

Steel tanks are strong. But they can rust over time. They were more common in the past. Here’s what to consider:

• Pick a coated tank. This helps prevent rust.
• Set a solid base. The tank should sit evenly.
• Install with care. Steel is heavy, so plan ahead.
• Check for corrosion. Look inside every year.
• Seal any gaps. Use sealants to stop leaks.

What Size Septic Tank Do I Need?

Following are a few most simple and accurate ways to consider picking the right size septic tank for your home:

Water Usage

Among several methods, the most accurate and effective way to follow to determine the right size septic tank is to calculate the amount of water used.

So measure the volume of water your tank will hold that need to be drained into the soil absorption field. 

In any area of the USA, the minimum size of septic tank allowed is 1000 gallons.

Considering the overall water usage of your household, you can pick the most preferred size from the list below:

Amount of water usage	The capacity of the tank
500 gallons per day	900-gallon septic tank
700 gallons per day	1,200-gallon septic tank
900 gallons per day	1,500-gallon septic tank
1,240 gallons per day	1,900-gallon septic tank

The Size Of The Property

Another reliable way to find the right size for your septic tank is to consider the square footage of your property.

It means the larger your property, the larger the size of septic tank you’ll need. 

For example, if your property is smaller than 1,500 sq ft, then you will require around 750 to 1000 gallon septic tank.

But if your property is bigger up to 2500 sq ft, then your septic tank should be larger than 1000 sq ft.

The Number Of Bedrooms The Property Has

Though it’s a less accurate method, still it helps to calculate the tank size. According to this method, the more bedrooms you’ll have, the larger your septic tank should be.

But it’s tough to say what size septic tank you’ll need as the water usage varies depending on the situation. 

For example, if you have three bedrooms and live alone, it doesn’t mean you’ll need a larger septic tank.

The main purpose of using this method is to aware a new house owner of the size of the septic tank he’ll need in the future. 

Number of bedrooms	Square footage of the property	Septic tank size
1 or 2 bedrooms	under 1,500 sq ft	750-gallon tank
3 bedrooms	under 2,500 sq ft	1,000 gallon tank
4 bedrooms	under 3,500 sq ft	1,200 gallon tank
5 or 6 bedrooms	under 5,500 sq ft	1,500 gallon tank

The Number Of Occupants

Likewise, the property, the more people in the house, the septic tank will be larger.

For example, if your family has two members, a smaller septic tank will be good enough.

But if your family has more than five members, you’ll require a bigger septic tank to handle the wastewater more hygienically and effectively. 

Minimum Septic Tank Capacity Chart

Let’s take a quick look at what size septic tank do I need based on the overall considerations

Number of bedrooms	Minimum liquid surface area	Drain field Size	Minimum Septic Tank Size
2 or less	27 Sq. Ft.	800 – 2500 Sq. Ft.	1000 – 1500 Gallons
3	27 Sq. Ft.	1000 – 2880 Sq. Ft.	1000 – 2000 Gallons
4	34 Sq. Ft.	1200 – 3200 Sq. Ft.	1250 – 2500 Gallons
5	40 Sq. Ft.	1600 – 3400 Sq. Ft.	1500 – 3000 Gallons
6	47 Sq. Ft.	2000 – 3800 Sq. Ft.	1750 – 3500 Gallons

Estimated Cost

The cost of any services varies depending on the area you live in and the condition of the market.

If you consider a concrete septic tank, it’s the most common option yet has a longer service life. On average, 1000 gallon septic tank can cost from $500 to $700.

But you’ll cost a minimum of $100 for a 1,250-gallon tank.

After installing the right size septic tank, you may need to clean it every 3 to 5 years. So you have to consider an extra $75 to $150 on average to empty the tank. 

Fixing the budget will help you make the final decision appropriate. As said earlier, the size of the septic tank largely affects the overall system.

To make an accurate estimate of the size and budget, you can consult with your local contractor.

How To Maintain A New Septic System?

Though cleaning a septic tank isn’t your task but following these maintenance tips will help you avoid irritating experiences that may cause due to inaccurate septic tank system:

• Consult with an authorized professional to make a proper septic tank maintenance plan
• Schedule an inspection time of the septic system.
• Attach an effluent filter. This will not only reduce the volume of solid leaving the septic tank but also prolong its service life.
• Always use Energy Efficient Appliances and accurately dispose of waste materials 
• Clean the septic tank every two to three years by an experienced and licensed professional.
• Talk to a professional if you notice any problems with your septic tank system. It will be far better to prevent it in the bud rather than pay a large price later.
• Keep records of the repairs and inspections of your septic system.

FAQs

Final Words

The septic tank size we have suggested above is only a recommendation based on government regulations and research.

So there won’t be one size fits for all as these will aware of the minimal requirement based on the water usage, size of the area, and the number of bedrooms. 

So if you are wondering what size septic tank do I need, check the local rules first and then estimate the right size based on those considerations.