Hi all
I read a previous tread were Pieter meantioned that zeolite is actually for new filters but if it takes the ammonia out of the water is it not good to have it permanently in your filter with a bio filter. Naturally one will have to recharge it now and again. Then what about putting zeolite in a sand filter instead of koi sand? Could some one give some advice.

Thanks

Roy

Hi Roy, some people do that indeed but then one cannot use any salt in the water.

Hi Roy

Have a look here https://koionline.forumotion.com/all-your-questions-about-filtration-answered-f16/clinofish-t1603.htm

Cheers
Lee

Hi Roy - hi Wayne,

Roy that’s a good question.

Zeolite is an amazing substance. It will remove ammonia immediately from the water. The reaction is very quick. After a time the zeolite will become saturated with ammonia and not adsorb any more. Bacterial biofilms will grow on the surface - which looks a lot like Siporax, the ceramic media under a microscope - and the zeolite will become a media just like any other.

Zeolite can be used as chips in an open chamber for bioconversion instead of stone. Smaller chips - about 6mm in size can be used to replace the gravel in sand filters. Zeolite is lighter than gravel. Therefore when it is used in a sand filter, the filter bed will still trap the solids but will backwash and break up easier than gravel. I changed to zeolite about 18 months ago to try it. And it really works well.

Zeolite is used in the show tanks in the Holland Koi Show to keep the ammonia in check.

Zeolite and salt.

If you want to re-use zeolite to adsorb the ammonia you can re-charge it by placing it in a saturated salt solution. This will cause the ammonia ions to be released and replaced with the salt ions. You can then re-use zeolite over and over.

There is a myth about zeolite - i.e. you cannot use zeolite and salt in a koi pond. This is completely untrue. I corresponded with a scientist about 15 years ago about this. He was a world authority on zeolite - he lived in Port Elizabeth or East London at the time.

Many chemical formulas which were way above my head came back on my enquiries. But basically this is what he said -

In order for zeolite to release all the ammonia you have to place it in a saturated salt solution. (Hopefully you don't place your koi in a saturated salt solution).

Secondly the amount of ammonia released from the zeolite is directionally proportional to the amount of salt in the water.

Starting up with salt already in the water the opposite happens - the amount of ammonia zeolite can adsorb from the pond water is inhibited by the amount of salt already in the water.

If you have a saturated salt solution in the water your zeolite will not adsorb any ammonia and your fish will stop breathing as they dehydrate to death.

The next questions about the levels of salt some koi keepers use. This is usually 1 - 3kg per 1000 litres. This is the same as a 0.1% - 0.3% salt solution.

At this level of salt the release of ammonia is very, very small and not only this but the release of ammonia is very gradual.

So if you do have zeolite and it is saturated with ammonia and you do add a little salt a very small amount of ammonia will be released gradually. This ammonia will move through your filter system in a very short time and be converted to nitrite and then to nitrate as a normal course of events.

Hope this helps,
Chris

Hi Chris

Thank you for the information. What will we do without you



regards


Roy

I will second that

The Gentleman with all the knowledge and experience who is willing and keen to share!