I installed a Durso pipe in my tank about 7 months ago to take care of the noisy overflow. My filtration goes into my basement (about 50ft pvc hose) sump box to filter the water. Everything was working fine. Now when my power goes off/on, and the water fills back up into the tank, it overflows for about 5 seconds or so and then levels out. Not sure why this just started happening as no adjustments were made. Any ideas?