What is the long term effect on surrounding soil of backflushing the DE filter on a saltwater pool?

Answer 1

I have heard of gardeners who use DE to avert snails and slugs. The tiny chrystals are sharp and they hate it. I think the chemical composition is organic calcium. Some plants use lots of it, ie corn and citrus. Just for the record, DE is actually microporous silica (silicon dioxide), and contains no calcium. The individual particles are very abrasive though tiny, so DE is very damaging to slugs & such.

ANSWER::

The operative words above are silica - abrasive. Build up of this D. E. in the soil is hazardous to your health. It acts like fiberglass!! Once in the lungs it cannot be removed. Even if the D. E. is mixed into the soil the resulting dust from disturbing the soil can be breathed in. Children and pets can be harmed if allowed in that area to play especially if unsupervised. Even walking in an area covered in D. E. and getting it on your clothes thus can be transferred later to children or adults hours later. Ie: children who sit on your lap to be read a story or watch TV etc. Much like asbestos was years ago. Look up Mesotheiloma - not sure of spelling. Most communities prohibit the dumping or backwashing of filter aid ( D. E. or similar products) onto the ground. It must be disposed of in a bag in the trash or directly into the sewer. Check local codes for proper disposal of this product. A lot of communities are prohibiting the dumping or backwashing of pool water onto the ground or into the gutters. Again consult your city codes for this.

K