Weird issue.

[sewerman45]

Every time I turn off my main pump from my sump to my display tank and turn it back on, tons of white stuff is blown into my tank. It is tons of white feathery things that kind of disappear when you try to grab them. It clears up after about twenty minutes or so.

Is it calcium build up in the pipe back up to the tank? It's about 6 or 7 feet of 1" pvc. It doesn't seem to have any negative affect but I'm worried that it's a symptom of something. I thought maybe my magnesium was low but it seems to be fine. I do 2 part dosing. This has been happening since day 1.

Thanks for any help.