In a hot water system “here” you have a black anode (magnesium) for area’s with less than 600 parts per million of suspended solids (not sure of the correct expression , but the count is correct)any higher than that and the anode bubbles. Hence above that count you use a blue anode (aluminum). Its possible under those circumstances that given the unit with a black anode in an area with the count greater than 600ppm WILL create bubbling in the tank.
All advice is given with-out seeing the job, and hence all advice MUST be taken as advice with limited knowledge on the exact situation. NO responsibility can or will be taken. And yes, I am a licensed Plumber and Drainer with my own business in Brisbane Australia.
Try visiting ….
http://www.internut.com.au … http://www.prostate-healthcare.com … http://www.ebookmegastore.com