Well from what ive learned on this site is that it really doesnt matter wether you use the skimmer now or after the cycle. Its just that you wont really pull anything out until at least the cycle is over. So save some money from the electric company and put it toward the skimmer. Ive heard nothing but bad things about the Seaclone. For a 40gal tank and the cost of the Seaclone, you may be better off getting the prism. is rated for up to 100gal, so say 75gal to be behind borderlines. That is more than you need, plus i believe its cheaper than the Seaclone.