[Nitrite spike after water change /vac]

The test before this test was pretty normal. Because im going away i thought if i lowered the nitrates a little it would cover me till i got back just raising a kittle 

[Nitrite spike after water change /vac]

I hadnt water vac in a while noticed alot of debree 27liter tank did 10liter  water vac change my nitrites spiked after water change after 2 hours checked it up again and did another smaller water change and tested 2 hours later nothing has changed it is a cycled tank. What do i do?