Thanks again everyone.Caecosystems is correct the yellow thing lower left is a Ball Sponge,its been in tank for over two years.Just some info I left out,tank is 85g AGA with a HOB overflow,4-96w PC's,started out with a wet/dry but 2 years ago Bioballs were removed,now its just a overpriced sump,cheap ventury type skimmer with a Mag 9.5 powering it,DSB in display tank with 120lb of LR.