Zeolite in a sand filter

[stev32k]

I'm wondering if anyone has used Zeolite as a replacement for sand in a sand filter. I've read claims that zeolite will filter down to 3 microns vs about 30 microns for conventional sand. Is this true? And has anyone actually tried it and are there any problems using it?

 

[JasonLion]

Zeo will certainly filter better than sand, though I don't know about 3 microns being realistic. People who use zeo divide into two groups, more than half really love it, but the remaining substantial minority have many problems and regret using it. It can make the water cloudy, apparently with crushed zeo dust.

 

[stev32k]

I've dealt with zeolite for many years in industrial water softeners used for boiler make-up water and know there can be a problem with the material breaking down and causing cloudiness in the effluent. That is due to the hardness of the specific zeolite. Some zeos are soft and break down easy others are very hard and won't break down. The problem is that hardness values are almost never published and trial and error is the only sure way I know of to tell the difference. I'm not sure I want to go that route with my pool.

It never occurred to me to use it in a sand filter. I've never seen any test data on it's filtering efficiency, but I am also skeptical about removing particles down to 3 microns.

 

[teapot]

Whilst I am not edorsing zeolite, the best quality and hardest comes from Werris Creek, NSW in Australia.

Whist all sorts of claims are made the facts that are known:
In a salt water pool you don't get ion exchange.
Chlorine combines with ammonia faster than zeolite can filter it.
It quickly reaches saturation point before removing all the ammonia.
Softer zeolites are nothing but trouble after a short time.
because of the complex structure it will become biofowled and will be very difficult to backwash clean although it will be good to start with.

 

[stev32k]

<<because of the complex structure it will become biofowled and will be very difficult to backwash clean although it will be good to start with.>>

Does this mean you don't recommend zeolite as a filter media?

 

[teapot]

Due to the huge area of filtration created by zeolite in a domestic pool it can take many years 8-10 before you need to change it so if that is ok then you do have good filtration up to that point. It definitely out performs sand but in a well set up pool sand also works very well (well enough for most)

I personal don't see why it should lower the backwash cycles or water usage and the more complex the filter surface the harder it is to clean. When I switched from sand to glass (Drydens AFM) which is expensive compared to almost all other forms of filtration there was a visible difference in the water and being glass it is easy to clean as the surface is smoother than sand or zeolite. I have another pool with sand nearly 8 years old which is reasonably maintained by the owners but gets rough treatment over winter and each year we get great results from the original sand.