Jacques, I use a stocking on my skimmer outlet pipe, it works wonders, but have to change it every 3 daysAgree with Warr - basically swap the skimmer location with the AC. The filter wool you want to use will only work IF you are 100% sure that you will be replacing or cleaning this at least every week.... Otherwise the filter wool will start leaching nitrates into the water.
I actually re-use them, I have about 10. Once changed gets soaked in Hot water overnight, then soaked in RO water till ready to go back in the tank.LOL! How many stockings do you cut up in a month?
Firstly - why do you want to use coarse sand in your DSB?shouldn't the coarse sand be on top of the finer sand to prevent the finer sand from blowing away?
Why not remove the all compartments - put your pump and ps on top of the sand bed. By doing this you have a larger dsb area (which is good). This once again is working very well for me.....
so this is what it should look like ???