Eheim Filter Media

I have an ecco pro 300 which has 3 media baskets.
 
When I set it up I need to put my old matured juwel filter sponges into 1 basket, which obviously means having to remove 1 of those eheim filter medias  sooo ---
 
Layer 1 is  -- subtrat pro which is bio and sintered glass
 
Layer 2 is --  Bio- mech which is half bio and half mech
 
Layer 3 is --  Mech pro which is little plastic things that remove large particals.
 
 
Which of these 3 above baskets is the least important that I can replace with old cycled filter sponge.
 
 
 


Oh here is a pic of the 3 baskets
 
 

only touch the top layer, it should just pack in with the filter wool. maybe you could remove a few bio balls and make a bit of room or not use the carbon pad as they only last a few weeks anyways. I have the ecco pro 300 and classic 250 and normally there is a little extra room in the top compartment to stuff sponges etc. When I replaced my internal with the 300 I ran both for a month then just removed the old one.
 

Yeah thnx.
 
Imma just cut it all up and push it into the top, I dun use carbon or anything anyways.
Only reason I'm doing it is to kick start it with matured media, so I'll just leave it in for 6 weeks or so then remove it anyways

You can replace the middle layer. Sponges are a mix of  bio and mech media. I replaced the noodles in one of my Eheim Pro II 2026 with sponges. But they use two large trays. The bottom tray tops off with a course blue sponge and the final stage in the next basket is a fine white pad.