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No. 8 Pea Gravel Filter Support Media, 1/4 × 1/8 in., 50 lb Bag
No. 8 Pea Gravel Filter Support Media, 1/4 × 1/8 in., 50 lb Bag
This listing is for one 50 lb bag of No. 8 filter support gravel sized from approximately 1/8 inch to 1/4 inch.
This is support gravel, not No. 20 filtration sand. Use it only in filters whose manufacturer specifically requires a gravel support layer. Confirm the required media size and total weight before ordering.
No. 8 Pea Gravel Filter Support Media, 1/4 × 1/8 Inch, 50 lb Bag
No. 8 pea gravel is coarse filter support media designed for compatible commercial, institutional and high-capacity swimming pool sand filters. It is installed as the lower layer of the media bed, beneath the finer filtration sand.
The gravel helps support the sand bed, surrounds the filter laterals or underdrain assembly and promotes even movement of water through the bottom of the filter. Each bag contains 50 pounds of gravel sized between approximately 1/8 inch and 1/4 inch.
What Support Gravel Does
- Forms the lower layer of a specified filter-media bed
- Supports the finer filtration sand above it
- Surrounds compatible laterals and underdrain components
- Helps distribute water through the bottom of the media bed
- Helps reduce fine media migration toward the underdrain
Common Applications
- Commercial swimming pool sand filters
- Institutional and municipal aquatic facilities
- High-capacity layered-media filtration systems
- Complete filter-media replacement projects
- Filters specifically requiring 1/4 × 1/8 support gravel
How the Filter Media Layers Work
Product Specifications
| Product Name | No. 8 Pea Gravel Filter Support Media |
|---|---|
| Product Type | Coarse support gravel for compatible filtration systems |
| Media Designation | No. 8 support gravel |
| Nominal Size Range | 1/8 inch to 1/4 inch |
| Bag Weight | 50 lb |
| Quantity Included | One bag |
| Position in Filter | Lower support layer beneath the filtration sand |
| Primary Application | Compatible commercial, institutional and high-capacity sand filters |
| Compatible Upper Media | No. 20 silica sand or other media specifically approved by the filter manufacturer |
| Installation Requirement | Use only when the filter manual specifies support gravel of this size |
| Not a Substitute For | No. 20 filtration sand, cartridge elements or diatomaceous-earth media |
| Not Intended For | Decorative landscaping, playgrounds or general construction use |
How Many 50 lb Bags Do I Need?
Find the required support-gravel weight in the filter manual, manufacturer data sheet or approved project specification. Divide that amount by 50 and round up to the next full bag when necessary.
| Required Support Gravel | 50 lb Bags to Purchase |
|---|---|
| 50 lb | 1 bag |
| 100 lb | 2 bags |
| 150 lb | 3 bags |
| 200 lb | 4 bags |
| 250 lb | 5 bags |
| 300 lb | 6 bags |
| 350 lb | 7 bags |
| 500 lb | 10 bags |
| 600 lb | 12 bags |
| 700 lb | 14 bags |
| 1,000 lb | 20 bags |
| 2,000 lb | 40 bags |
Support Gravel Is Installed Before the Filter Sand
Shut down the circulation system, isolate the filter and fully relieve internal pressure before opening the vessel. Follow the filter manufacturer’s safety, access and media-loading instructions.
- Remove the old media when performing a complete media change
- Inspect laterals, hubs, strainers and underdrain components
- Replace damaged or missing internal components before loading
- Verify that the filter vessel is clean and free of debris
- Add gravel slowly to avoid damaging internal components
- Spread the support layer evenly around the underdrain
- Add only the specified gravel depth or total weight
- Install the filtration sand above the completed gravel layer
- Follow the required backwash and rinse startup procedure
Not Every Sand Filter Uses Support Gravel
Many residential sand filters are filled entirely with No. 20 silica sand and do not require a separate gravel layer. Other commercial and high-capacity filters require a specific combination of sand and support gravel.
Do not add gravel solely because the vessel is large or because another filter uses it. Confirm the exact filter model, media specification, gravel size, gravel weight, sand weight and loading sequence before installation.
Frequently Asked Questions
What is No. 8 filter support gravel used for?
It is installed as the lower layer in compatible layered-media sand filters. The gravel supports the finer sand above it, surrounds the underdrain or lateral system and helps distribute water through the bottom of the filter bed.
Is this the same product as No. 20 filter sand?
No. No. 8 support gravel is much coarser and is used beneath the filtration sand. No. 20 silica sand is the finer upper media layer that performs most of the particle filtration.
What does 1/4 × 1/8 inch mean?
It identifies the nominal gravel particle range. The media is sized between approximately 1/8 inch and 1/4 inch for compatible filter support-layer applications.
How much gravel is included?
This listing includes one 50-pound bag. Increase the order quantity to purchase the number of bags required by the filter specification.
Does every commercial sand filter require support gravel?
No. Requirements vary by manufacturer and filter design. Some commercial filters specify a sand-and-gravel media bed, while others use sand alone or a different layered-media arrangement.
Can this be used in a residential pool sand filter?
Only when the residential filter’s manufacturer specifically calls for a 1/4-inch by 1/8-inch support-gravel layer. Do not add it to a filter designed to use No. 20 sand only.
Which media is installed first?
In a filter designed for this layered arrangement, the support gravel is installed first around the underdrain. The finer filtration sand is then installed above the completed gravel layer.
Can I use ordinary landscaping pea gravel?
Ordinary landscaping gravel should not be substituted. Filter media must meet the size, cleanliness, screening and material requirements specified by the filter manufacturer or project engineer.
How do I calculate the number of bags?
Divide the required gravel weight by 50. Round up to the next whole bag when the result contains a fraction. Add only the exact amount specified for the filter.
Should the filter be backwashed after installing new media?
Follow the manufacturer’s startup procedure. Most sand-filter media changes require an initial backwash and rinse before the filter is returned to normal filtration service.
Not Sure Whether Your Filter Requires Support Gravel?
Locate the filter manufacturer, complete model number and media-loading specification before ordering. Commercial filters may require separate gravel and sand weights.
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