I have a Aqua Euro classic 135 on my 55 gallon tank and sump. IT was working just fine until about three weeks ago. The water level in the skimmer rises on it's own. I have it lower to the lowest water level and then in 30 minutes the water level rises and flows out the overflow spot. IT never get to the collection cup. Does anyone know a reason why this could be happening. I havent changed anything in my tank or sump.
