Nicole’s Advice

I often get asked which is the best media to choose for filters. We stock both sand and various glass options in store. My personal advice is to choose any type of glass media, not just because it is recycled but it filters to a finer particle size and increases time between backwashing to make life easier.

Another question I get asked a lot once people choose glass media, is if they choose the brands that supply coarse and fine, which do you put in first. The answer is coarse goes in first, as that will go near the laterals. Some glass media is all one grade, and then it does not matter at all.

Here is why the experts think glass is the best choice

Choosing glass media can it improve your pool water’s clarity, but it can also reduce maintenance times, lower chemical costs and decrease your energy bills. 

What is glass filter media?

Made from grains of recycled glass, glass media is used in media filters to keep debris and bacteria out of your pool. As water is pumped to the filter, it passes through the glass media, which captures particles using a static charge. The clean water is then syphoned back into the pool through the return jets.

In the past, media filters were considered less effective than cartridge filters or diatomaceous earth (DE) filters. This is because sand media didn’t capture as much as other filters. While it was affordable and readily available, it only filtered about 20–40 microns. This was less than DE filters, which could filter particles as small as 5 microns. In addition, sand could erode, clump or create channels of unfiltered water, reducing its effectiveness over time.

When glass media was introduced in the 1990s, it matched DE’s filtration powers (without being as costly or high-maintenance). Since then, glass filtration has grown in popularity, not just because it works well, but also because it provides a range of benefits, not just for your pool, but also for your finances and the environment.

Benefits of glass filter media

Whether you’ve just installed a new pool or you’ve had one for years, here are eight reasons why suppliers like Astral say you should  choose glass media 

1. Low maintenance 

Unlike cartridge filters, which require regular rinsing (or overnight soaking if they’re really dirty), glass media only requires backwashing every couple of months. This can take as little as five minutes, depending on the size of your pool. What’s more, glass media only needs to be replaced every 8–10 years, while cartridge filters need to be replaced every 2–3 years. This means less monthly maintenance.

2. Long-lasting

Most media filters come with a 10-year warranty, which is longer than the lifespan of a standard cartridge filter (about 2 years). Glass media itself can last for 8–10 years because it’s made from recycled glass bottles. These are harder than standard glass and less prone to erosion. On the other hand, sand media can start to break down after about 5 years. This means that media filters can last 5 times as long as cartridge filters, and glass media twice as long as sand on average.

3. Improves water clarity

Glass filter media can remove particles as small as 5 microns in size, which keeps your pool water healthier and clearer. By comparison, sand only filters about 20–40 microns and cartridge filters filter about 10 microns. (FYI: A speck of dust can be about 40 microns and unicellular green algae can be 5–10 microns.)

There are a couple of reasons why glass media can filter more effectively. First, glass doesn’t pack as densely as sand. In other words, it uses the entire depth of the filtration media, while sand only uses the top layer. This means that it traps more particles as water passes through.

Second, glass media has a negative charge that attracts particles more readily. This means it can trap 30 per cent more debris than conventional glass, keeping your pool cleaner.

4. Sustainable

Most glass media is made from durable recycled glass. Not only does this put less pressure on our natural resources, but it also reduces landfill. And because glass media lasts longer than sand or cartridges, you don’t have to replace it as frequently, making it an eco-friendly choice for your pool.

5. Reduces backwashing

Compared to sand filters, which require backwashing every 1–2 weeks, or cartridge filters, which need to be cleaned monthly, glass media usually only needs to be backwashed every 2–3 months. The duration of the backwash is also shorter because glass is smooth and allows the easy passage of water.

6. Prevents bacterial growth

Glass media is less permeable than sand, which means that debris like suntan lotion or bacteria can’t get ingrained. Instead, glass holds onto the debris with a static charge. This allows it to come off easily during backwashing.  Sand grains, on the other hand, are porous, making them a breeding ground for bacteria – particularly if you don’t backwash them often enough.

7. Economical

While there’s a higher upfront cost with glass media, you don’t have to replace glass or backwash it as often as sand. The backwash also happens at a lower speed, which reduces energy consumption. And because glass media keeps your pool cleaner, you won’t need as many chemicals to keep your  water balanced, nor will you have to run your pool cleaner as often. This can save you hundreds of dollars in water, energy and chemical costs every year.

8. Easy to convert to a mineral pool

Mineral pools perform best with glass media filtration, so if you’re already using glass media and planning to convert to a mineral pool, you can do this with minimal effort or expense. All you need is a chlorinator (if you don’t already have one) and minerals.