prefilter bag for overflow help

I just converted my 85g sumpless system to a 125g with built in overflow and 35g sump. I was told to change my prefilter bag that the overflow runs into once a week to eliminate nitrite and nitrate build up. I changed one the bags out already and washed it in my clothes washer with a little chlorine bleach. I also then ran it through the washer 3 more times to get rid any chlorine bleach. Well it's been another week and I changed the bags out again. I removed the dirty bag and placed in the new clean one. My skimmer started going nuts, it was overflowing producing lots of bubbles. Its an euroreef cs6-2. Even on the lowest setting it was still overflowing with bubbles.

Here are the questions:
1. Did I screw up by washing it with chlorine bleach?
2. Did I maybe not rinse it out enough?
3. What future method should I used to clean the prefilter bag?

amonia, nitrites and nitrates are 0.
i have a 110lbs of live rock

don't u need the prefilter bag so u don't get excess food or sand in your skimmer and return pump as not to damage them or clog them up?

after only 1 reply and talking to some people at my local store. I am removing the prefilter bag as recommended. They said the size of my pumps wouldn't be harmed.

It's gone! Thanks!