Im currently treating my tank for a minor ich outbreak and had to remove the carbon from my 2 Penguin 200s. Ive supplemented the filter cartridges with floss and also installed a power head with a sponge filter attached to increase circulation and aeration. Im considering leaving the power head and sponge combo in permanently. Aside from the obvious water change, should i replace the sponge after treatment? Im afraid of the possibility ich may stay in the sponge and turn up again.