Hi
I have the juwel rekord 800 and my internal filter contains the blue sponge at the bottom, the green in middle and white wool like filter on the top.
Tbh i really dont rate the Jewel internal filter all too highly but it will be fine for a medium stocked tank
I plan to replace mine soon with an external
anyway back on topic.
There is no need to replace the filter sponges until they fall apart. I personally give each sponge a few sqeezes every water change but i rotate so i am only sqeezing one sponge per water change
The white wool filter media can and should be sqeezed every water change otherwise i have noticed the flow rate of the filter can drop quite a bit. (I replace the white one about every 6 weeks)
Oh and also..Aim the nozzle of the filter upwards so it disturbs the water surface and helps oxygenate the water
Good luck and have fun