Hello i have a stingray 10 and stingray 15 internal filters.infact here is one of them: http://www.maidenheadaquatics.co.uk/eshop/...products_id=157 as it said it has carbon and zeolite cartridges which i replace every 2 weeks but as you can imagine is gets very expensive .everyone i socilise with who have fish and these or simular filters told me not to change them so often.some said a month,some said a month and a half.but i could never leave it more than a month and even then im worried as i know this one of the most important things as it hold ammonia and im worried if i leave it too long it will start leaking out the ammonia its asborbed. then someone told me a good way to cleanse them in between new ones is to leave them in hot saltwater for 12 hours.but she didnt know what salt to use,what ratio of salt to water ,or was sure if it was 12 hours,and didnt know how it would affect the zeolite,as she doesnt know what it is (nor do i for that fact). so i decided it really wasnt a good idea untill i know all the facts.as i would hate to do it then put it back in when its still releasing ammonia,or for some sorta chemical reaction with the zeolite. so im gonna scan the net and look for some info and find out what zeolite is! lol. if anyones has any knowledge on this matter or ideas or general input ,all help will be most appreciated.cheers xxx

Salt will release all the organic matter in the carbon but I don't know if that would make it reuseable. I've never heard it done before, most likely the carbon would just fill up with salt and make it useless. Same with the zeolite.

Your filter does contain regular foam to act as a biological filter so it will still keep working long after the carbon and zeolite are full. In fact, once the carbon and zeolite are inactive they will just become part of the biological filter with bacterial growing on them.

I don't recommend the use of zeolite at all, absorbing the ammonia will only handicap the natural cycle of your tank. You may want to consider a new type of filtration, in the meantime change the carbon/zeolite pads as little as possible, rinse them thoroughly like you do the foam pad and just keep reusing them.