bottom- coarse sponge
middle- bio level (broken ceramic rings)
top- filter floss.
this is because the water flow starts at the bottom and flows upwards. so big debris will get caught at the bottom first and then the finer stuff last.
middle- bio level (broken ceramic rings)
top- filter floss.
this is because the water flow starts at the bottom and flows upwards. so big debris will get caught at the bottom first and then the finer stuff last.