i just set up a surface skimmer in my little 10g planted tank, and it's not working correctly no matter what i try. it just works for a few seconds before losing suction and sucking in air and doing nothing for a few seconds before repeating the cycle again. i tried adjusting the flow on the skimmer, but it does nothing. the hoses are in the same place as they were before, except now there's the extra tube leading from the hose to the skimmer. has anyone had this problem before?