Help with filter sponges

I have a hozelock 9000 biofliter.
The sponges were old so I got some new ones.
The old ones 3 are green and flat.
The new ones 4 are flat the one side and dimpled the other.
Does it matter which way up I put them
I no not to change them all in one go.

 

Yes Lyn, dimples up

 

With any sponge filter the dimples face into the flow the coa*rse filter(if they're different grades) first, it presents a bigger surface area of filtration.

 

Thank you .
I did start to put them in dimples up but thought i should check.

 

An update.
These new filter sponges are fantastic.
The pond as never been so crystal clear.
I can't believe the rubbish they are getting out. :thumb: