Drain via backwash

[StoshJ]

I'm going to eventually need to drain 1/2 my pool in order to bring my calcium levels down. I was wondering if I could just drain via backwashing (DE). I'm hesitant since the manual says not to run the filter without DE for more than 5 minutes, and I'm not sure if backwashing is considered the same as if it were filtering. I don't have a bypass valve, just filter/backwash.

Thanks...

[Rangeball]

Any way you can disconnect the inlet to the filter from the pump and just use the pump to get rid of the water?

[matt4x4]

There are some chemicals that will drop out the calcium as a solid and all you have to do is vac to waste. (TSP or Hydroquest, i believe)
If you had a sand filter, you can also use Zeolite/zeobrite instead of sand, it actually grabs the calcium in a bond, like a softener would, you can then add salt to your filter (system off of course) and let that sit for a bit, then backwash and the calcium will get washed out.