Understanding cisterns means knowing key terms like ‘capacity,’ ‘material,’ ‘installation,’ and ‘maintenance.’ This guide breaks down these essential cistern words for beginners, making choosing, using, and caring for your water storage solution simple and effective.
Navigating the world of water storage can bring up a lot of new words. If you’re just starting to look into cisterns for your home, you might feel a little lost with all the jargon. Don’t worry, it’s completely normal! From understanding how much water one can hold to knowing how it fits into your home, there are a few key terms that make all the difference. This guide is here to clear things up, making cisterns easy to understand. We’ll walk through everything you need to know, step by step, so you can feel confident about your choices.
What Exactly is a Cistern?
At its heart, a cistern is a tank or container used for storing water. Think of it as a special water reservoir for your home. Historically, cisterns were often built underground to collect rainwater from roofs. Today, they serve many purposes, from storing potable (drinkable) water to holding water for non-potable uses like gardening, flushing toilets, or firefighting. They are incredibly useful, especially in areas where consistent water supply can be a concern or for those looking to be more sustainable by collecting rainwater.
Why Learn Cistern Terms?
Knowing the basic terms related to cisterns is crucial for a few reasons. Firstly, it helps you make informed decisions when purchasing or installing a cistern. You’ll understand product descriptions, get accurate quotes, and ask the right questions. Secondly, it’s vital for maintenance. Understanding terms related to cleaning, common issues, and repairs ensures you can keep your cistern in good working order, guaranteeing a safe and reliable water supply. Finally, it empowers you to communicate effectively with professionals, ensuring you get the service and solutions you need without confusion.
Essential Cistern Terms Explained for Beginners
Let’s dive into the specific terms that will help you understand cisterns better. We’ll break them down into logical categories, from what a cistern is made of to how it works and how to care for it.
Cistern Components and Types
Understanding the different parts and kinds of cisterns available is the first step.
- Tank/Cistern Body: This is the main container that holds the water. Cisterns come in various shapes and sizes, from large underground tanks to smaller above-ground units.
- Capacity: This refers to the maximum volume of water the cistern can hold. It’s usually measured in gallons or liters. Choosing the right capacity depends on your water needs (e.g., daily consumption, irrigation).
- Material: Cisterns are made from different materials, each with its pros and cons. Common materials include:
- Polyethylene (Plastic): Lightweight, durable, resistant to corrosion, and often the most affordable option. They are UV-stabilized for outdoor use.
- Concrete: Very durable, long-lasting, and can be built to custom sizes. They are excellent for underground installations and naturally keep water cooler.
- Fiberglass: Strong, lightweight, and resistant to corrosion. Often used for underground or above-ground applications.
- Steel (Galvanized or Coated): Strong and can hold large volumes, but may be susceptible to rust if not properly coated or maintained.
- Lid/Cover: An essential safety feature to prevent debris, animals, or children from entering the cistern. It should be secure and watertight. For underground cisterns, the cover often forms part of the access point.
- Inlet Pipe: This is where water enters the cistern. For rainwater harvesting, this pipe comes from your roof’s gutter system. For other uses, it might be connected to a well pump or municipal supply (though this often requires specific regulations).
- Outlet Pipe: This pipe carries water from the cistern to where it’s needed. This could be to your home’s plumbing system, an irrigation system, or a pump.
- Overflow Pipe: If the cistern fills up completely, the overflow pipe allows excess water to drain away safely, preventing damage to the cistern or surrounding areas.
- Vent: A small opening that allows air to enter and exit the cistern as water levels change. This prevents vacuum formation and allows for proper filling and draining.
- Access Hatch/Manhole: A secure opening that allows for inspection, cleaning, and maintenance of the cistern’s interior.
Installation and Setup Terms
Proper installation is key to a functional and safe cistern system.
- Site Preparation: This involves clearing and leveling the area where the cistern will be placed. For buried cisterns, it includes digging the excavation to the correct depth and dimensions. A stable, well-drained base is crucial.
- Foundation/Base: A solid base (like a concrete pad or compacted gravel) is necessary to support the weight of a full cistern and prevent it from shifting or settling unevenly.
- Plumbing Connections: This refers to connecting the inlet, outlet, overflow, and any other necessary pipes to the cistern and to your existing water system or drainage.
- Backfilling (for buried cisterns): Once the cistern is in place and connected, the excavated hole is filled in with soil or sand. Proper compaction is important to prevent settling.
- Sediment Trap/Filter: Often installed in the inlet line, especially for rainwater harvesting, to catch leaves, grit, and other debris before they enter the cistern, keeping the stored water cleaner.
- Pump System: If your cistern isn’t gravity-fed, you’ll need a pump to move water from the cistern to your point of use. This could be a submersible pump (inside the cistern) or a surface pump.
Water Quality and Maintenance Terms
Keeping your stored water safe and the cistern in good condition requires understanding these terms.
- Potable Water: Water that is safe to drink and use for cooking and hygiene. Cisterns storing potable water must meet strict health and safety standards, including regular testing and treatment. For information on water quality standards, the U.S. Environmental Protection Agency (EPA) provides valuable resources regarding the Safe Drinking Water Act.
- Non-Potable Water: Water that is not safe for drinking, cooking, or direct personal contact. This water is typically used for irrigation, flushing toilets, or industrial processes.
- Filtration: The process of removing impurities from water using physical barriers or chemical processes. Different filters are used for different purposes, from coarse debris removal to fine sediment or even microbial purification.
- Disinfection: The process of killing harmful microorganisms (like bacteria and viruses) in the water. Common methods include chlorination, UV treatment, or ozonation. This is critical if the cistern is intended for potable water.
- Sludge/Sediment: A layer of accumulated debris, silt, and organic matter that can settle at the bottom of the cistern over time. Regular removal is part of maintenance.
- Algae Growth: Microscopic plants that can grow in water exposed to sunlight, leading to green water and potential taste/odor issues. Opaque cisterns and keeping lids secure help prevent this.
- Water Testing: The process of analyzing water samples to check for contaminants, pH levels, and other indicators of water quality. Essential for potable water cisterns.
- Desludging/Cleaning: The process of removing accumulated sludge and sediment from the bottom of the cistern. This is typically done annually or bi-annually depending on water source and usage.
Operational Terms
How the cistern functions day-to-day.
- Rainwater Harvesting: The system of collecting and storing rainwater from rooftops. This typically involves gutters, downspouts, and filtration before directing water to the cistern.
- First Flush Diverter: A device that diverts the initial flow of rainwater from the roof, which is usually the dirtiest, away from the main storage tank.
- Gravity Feed: If the cistern is positioned higher than the point of use, water can flow out using gravity alone, eliminating the need for a pump.
- Pressure Tank: Often used in conjunction with a cistern pump. It stores water under pressure, allowing for consistent water flow and reducing the cycling (on/off) of the pump.
- Water Level Indicator: A gauge or device that shows how much water is currently in the cistern.
Understanding Cistern Materials: A Comparison
The material of your cistern significantly impacts its cost, durability, and suitability for your needs. Here’s a table to help you compare the most common options.
| Cistern Material | Pros | Cons | Typical Use Cases |
|---|---|---|---|
| Polyethylene (Plastic) | Lightweight, easy to transport and install, corrosion-resistant, generally affordable, smooth interior surface reduces bacterial growth. | Can be susceptible to UV degradation if not treated, may require anchoring in windy areas, can expand/contract with temperature changes. | Residential rainwater harvesting, non-potable water storage, suburban and rural homes with moderate water needs. |
| Concrete | Extremely durable and long-lasting, can be custom-sized, good thermal mass for stable water temperature, resistant to corrosion and pests. | Heavy and difficult to transport/install, more expensive upfront, can develop cracks over time if not properly built or maintained, may be porous if not sealed correctly. | Large-scale water storage, underground installations, areas requiring high durability and longevity, commercial applications. |
| Fiberglass | Strong yet lightweight, corrosion-resistant, smooth interior, durable for underground and above-ground use. | Can be more expensive than plastic, requires careful handling during installation to prevent damage, potential for buoyant issues if not properly ballasted when buried. | Residential and commercial water storage, underground applications, areas where corrosion resistance is paramount. |
| Steel (Galvanized/Coated) | High strength, capable of holding very large volumes of water, durable when properly coated. | Susceptible to rust and corrosion if coating is damaged, heavier than plastic or fiberglass, can be more expensive. | Large industrial or agricultural water storage, fire suppression systems (where massive volumes are needed). |
Step-by-Step: Basic Cistern Maintenance
Regular maintenance ensures your cistern provides clean water and lasts for years. Here’s a simplified guide for beginners.
Step 1: Visual Inspection (Monthly)
What to look for:
- Check the exterior of the cistern for any cracks, signs of damage, or leaks.
- Ensure the lid is securely in place and free from obstructions.
- Inspect inlet and outlet pipes for any obvious blockages or damage.
- If you have a water level indicator, check that it’s functioning correctly.
Step 2: Gutter and Inlet Screen Cleaning (Pre-Rainy Season and Quarterly)
Why it’s important: This is crucial for rainwater harvesting systems.
- Clean out your roof gutters and downspouts to remove leaves and debris.
- Check and clean any screens or filters on the inlet pipe that catch larger debris. A clean screen prevents your cistern from filling with unnecessary gunk.
Step 3: Basic Cistern Cleaning (Annually)
This is a more involved process and may require professional help for larger or underground cisterns. For smaller, accessible cisterns, here’s a general idea:
- Drain the Cistern: Use the outlet valve or a pump to empty the cistern as much as possible, leaving a small amount of water at the bottom to help with scrubbing.
- Remove Sludge: Use a shovel or wet/dry vacuum to remove the accumulated sludge from the bottom. Dispose of this material properly, as it can be quite thick and contain sediment and organic matter.
- Scrub the Walls: Use a stiff brush and a mild, non-toxic cleaning solution (like diluted bleach or a specialized cistern cleaner) to scrub the interior walls and floor. Rinse thoroughly with clean water. For potable water cisterns, ensure any cleaner used is approved for such use and that rinsing is extremely thorough. For more information on water treatment, the Centers for Disease Control and Prevention (CDC) offers guidance on safe drinking water practices.
- Rinse and Refill: Rinse the cistern multiple times with clean water to remove all traces of cleaning solution. Then, refill the cistern.
- Re-establish Water Treatment (if applicable): If you treat your water (e.g., with chlorine or UV), ensure your treatment system is functioning correctly after refilling.
Safety Note: Always wear appropriate personal protective equipment (PPE) such as gloves, eye protection, and a mask when cleaning a cistern, especially when dealing with cleaning chemicals or disturbing settled sediment. Ensure good ventilation if working in an enclosed space.
Step 4: Water Quality Testing (Annually for Potable Water)
Why test? Ensures the water is safe for its intended use.
- Send a water sample to a certified laboratory for testing.
- Test for common contaminants relevant to your water source and local conditions (e.g., bacteria, nitrates, pH).
- Take corrective action if test results indicate issues.
Common Cistern Problems and Solutions
Even with good maintenance, you might encounter a few issues. Here are some common ones:
- Foul Odor or Taste:
- Cause: Bacterial growth, algae, decomposing organic matter, or improper disinfection.
- Solution: Thorough cleaning, desludging, and ensuring proper filtration and disinfection. For rainwater, check your roof and gutters for sources of contamination.
- Low Water Pressure:
- Cause: Clogged inlet/outlet pipes, failing pump, air in the system, or a partially blocked cistern outlet.
- Solution: Inspect and clean all pipes and filters. Check the pump’s performance and prime if necessary. Ensure the cistern outlet isn’t blocked by sediment.
- Water Leaks:
- Cause: Cracks in the cistern body, faulty seals on pipes, or damage to the lid.
- Solution: For minor cracks (especially in plastic or fiberglass), specialized sealants might work. For significant damage or concrete cracks, professional repair or replacement is usually needed. Ensure all pipe connections are watertight.
- Sediment in Water:
- Cause: Ineffective pre-filtration, disturbed sediment during refilling, or a cistern that hasn’t been cleaned in a while.
- Solution: Improve inlet filtration (e.g., add or upgrade sediment filters, use a first flush diverter for rainwater). Perform a thorough desludging and cleaning of the cistern.
Cisterns vs. Water Tanks: What’s the Difference?
The terms “cistern” and “water tank” are often used interchangeably, but there’s a subtle distinction worth noting, particularly in historical context and common usage.
- Cistern: Traditionally, a cistern was a structure built to hold a large reserve of water, often for emergency use (like firefighting) or long-term storage. Historically, they were commonly built underground or integrated into buildings, often collecting rainwater. The term implies a more permanent or structural aspect.
- Water Tank: This is a broader term for any container designed to hold water. It can be above ground, underground, small, large, temporary, or permanent. Modern water tanks are very common for rainwater harvesting, home water supply, and industrial uses.
In modern DIY and homeowner contexts, most new water storage solutions for homes would be referred to as “water tanks,” especially for rainwater harvesting. However, the term “cistern” is still widely understood and used, particularly for underground storage or larger water reserve systems.
Frequently Asked Questions (FAQ) about Cisterns for Beginners
1. Do I need a permit to install a cistern?
Answer: Regulations vary significantly by location. Some areas require permits for water storage systems, especially for potable water or large capacities. It’s always best to check with your local building department or environmental health agency before installation.
2. How often should a cistern be cleaned?
Answer: For potable water, annual inspection and cleaning are highly recommended. For non-potable water (like for irrigation), cleaning every 2-5 years may suffice, depending on the water source quality and sediment buildup. Regular visual checks are always advised.
