What is the chemical I use while backwashing?

[jaxpool]

We've had our pool for 9 months and I'm still not sure of the name of the powdery chemical we put in our filter when we backwash, I need more and I don't know what I'm suppose to buy!!! Can anybody please help me? Thanks!!

[dynamictiger]

D.E. or Diatomaceous Earth is what you mean.

HTH

[jaxpool]

Thanks dynamictiger! Now just one more question when do I put the D.E. in the pool, before or after backwashing?

[Buggsw]

You put it in the skimmer after you backwash. So what you should do is backwash until the water runs clear. Close the backwash valve and run the pump for a minute like normal, then backwash again until clear and repeat one more time. Then you close the backwash valve and run the pump and load the DE in the skimmer. Some people like to make a slurry in a bucket of water first. I just poured it in with a 1 lb coffee can as a measure and let it slurry itself in the skimmer. Then add the next 1lb coffee can full, etc. However many lbs your filter needs to reload. Don't get carried away.

What it is doing then is reloading the filter with fresh DE.