I just realized this post has been here awhile without a response......

I can't help with the workings of the DE filter--I'm a sand filter fan myself. As to your water, how does it look now? Have you continued with your conversion? Basically, to convert from the Baq, you put enough chlorine in the water (we recommend bleach) to get to 10 ppm (15 if you don't have a vinyl pool), and keep it there by testing and adding 2-3 times daily, with the filter running and being backwashed as needed. By all accounts I've read over the past several years, the water tends to turn all kinds of weird colors, and you're not the first that has reported brown. Unless you have metals in your water, my advice is to keep pouring the bleach to it until it starts to turn blue and you can hold a chlorine residual. If you have metals in the water, then you also must use a sequestrant before raising your chlorine that high, in order to keep the metals in suspension in your water. Once the sequestrant has been added, then you can progress with the shocking. HOpefully your filter wll take care of the brown scum you already have--just keep in mind that one important part of the conversion process is changing the filter media when it's over, so if it's gotten the scum out, don't worry about it, just keep adding the chlorine.

Janet