Does it make a difference? I emptied out my sand filter today looking for a possible broken lateral. Turns out, they just weren't pushed all the way down, so the sand (and dust and dirt and stuff I thought was mustard algae) was getting spit back into the pool.
This was likely due to the former owner not reinstalling the lateral assembly correctly after changing the sand a few years ago. So, in order to make sure everything is put together correctly, I'm going to weigh the sand that I've got to make sure that the correct amount is in the filter. I've got a HaywardS180T and there's no fill line on the inside of the barrel, it's just a matter of putting the proper weight in there.
How much weight in water can the sand hold? Do I have to weigh it dry, or is the difference small enough that it doesn't matter?