Betty boo

16x48 vinyl above ground pool. New liner came with 1 large out let hole, and 2 small intake holes. Pump connects to 2 large. Tried connecting the 2 small to a split valve.Bad move valve leaks and can't turn off. Thinking of enlarging 1 of the small holes and plugging the other. Then I can hook the filter up to the pool with the 2 1 /2 in hoses. Any ideas? Pump is sand filter