I have questions about filter maintenance in my new tanks. Filter on the first tank
The filter on one tank (35 litre) has the water going in one side through a chamber of "bio-balls", then another chamber with a bag of carbon wrapped in filter material, then a chamber of "bio-rings". The water goees in one side and comes out the other.
The instructions that came with the aquarium says to replace the carbon and filter material every month and just to rinse the bio balls and bio-rings in tank water and rinse all of the pipes under the tap. Filter on the second tank
The filter on the other tank (75 litre) has a grid, then a sponge on top, then some "ceramic noodles" (basically the same thing they call "bio-rings in the other one) then a cartridge which has carbon and filter material sealed up together in a plastic frame. The water comes out of a tube with holes (they call it a spray bar) over the top through the filter material and into the tank. The instructions for this tank say to rinse the sponges in tank water, rinse the carbon cartridges under the tap every week, and to replace the carbon cartridges every 6-8 weeks. Questions
From what I've read, I thought it was a good idea to keep your filter material until it doesn't work properly any more, because that's where a lot of the good bacteria are.
If I replace the filter material and cartridges every month or 6-8 weeks as per the instructions, won't I be losing the good bacteria? Or is there enough on the sponge and ceramic noodles to make it ok to throw out the filter material every month?
Should I follow these instructions, or do something differently?
Is there any reason that in the second tank I couldn't put some carbon in a bag and put a loose layer of filter material on top (I have a big sheet of it) instead of buying the manufactured cartridges?
I'd appreciate any advice. Thanks.