OK, makes sense
Filter = it's sucking in and running water through the filter
Open means it's just pumping around, no filtering (good for adding lots of chemicals)
Waste means it's just dumping out water without filtering or backwashing.
Backwash will run the water backward through the filter and hopefully reduce schmutz on the media (sand)
Once your pressure gets high enough (say 10 pounds or so above where it was with new sand) you should backwash.
Here's an owners manual that should help you some. It may not necessarily be for your system, but they are all pretty much the same.
http://images.google.com/imgres?imgurl=http://www.pool-filters.com/images/hayward-s200-sand-filter.gif&imgrefurl=http://www.pool-filters.com/pool-filter-sand-hayward-s200.htm&h=250&w=215&sz=16&hl=en&start=1&tbnid=JJCNY4zXx0_haM:&tbnh=111&tbnw=95&prev=/images%3Fq%3Dhayward%2Bsand%2Bfilter%26svnum%3D10%26hl%3Den%26lr%3D
Awesome, thanks bunches!!!!!!!
No anything about "saltwater" pools?
