What Do Filter Crystals Do?

[meola]

I have a Rena superclean 40 internal filter. It has a sponge at the bottom and an "API Crystal" cartridge in the middle.

I presume when people talk about filter media this means the sponge.

What does the API Crystal actually do? And do I really need to change this every 3 weeks as per instructions?? Do I even need it at all?

thanks..

 

[frogmarch1987]

The 'API crystal' used to be called "Biochem Zorb'.

From what I understand, it's marketed as a better solution than carbon for removing unwanted odours, colours etc. from your tank.

However, you shouldn't put this cartridge in your tank at all. It's a waste of money as you don't need it for the normal running of your tank.

The only time you would use it is if you have used medications in your water, and then you would use the cartridge to remove the excess meds from the water once you've treated any disease. You may also use it to remove an odour from your tank which you can't find the cause of.

These carbon-type cartridges can only hold so much, before they get 'full' and start letting their stored chemicals back into the water. If you use your cartridge to remove meds etc (which should only take 24 hours) I would recommend throwing it away and getting a new one to store in the cupboard, to ensure it will be working at it's best if you need to use it

 

[meola]

makes perfect sense. old cartridge is going straight in the bin. thanks

 

[waterdrop]

Actually, the story of the carbon (or other molecular-charge-based resins) getting full and then releasing its stored chemicals back in to the water gets exaggerated (or mis-told, depending on how you take it.) Bignose did a nice little presentation about this in the scientific section once. WD
edit: I agree with the advice given though