Hello guys,
I am new in here and this is my first time to post. I am running a Mits wire edm MD Pro 3 for about a year or so and start to notice that the water in the working tank wont hold up to the upper head like it used to be. I dont know what's wrong with it. My part will get rusted if the water level drop below the work piece when the program finish at night. I changed new filters and keep my machine really clean all the time. Everything work great. Please help me out and give me some tips

Thank you guys