surreyboy wrote: ↑Mon May 08, 2017 6:13 pm
and the pumps don't like it much either. Granules put directly into the skimmers are also a no-no to my mind, as the pump and filter will complain unless the granules have dissolved completely,
That is exactly why pumps have course filter baskets to protect the impeller, if you are worried about the pump impeller being damaged by very small gritty bits, too small to be caught by the basket - you should not vacuum your pool. As to the filter being damaged - its full of gritty bits already.
Following a post I read somewhere else, during this last winter I put a floater in the pool with a couple of tri-chlor tablets around the time our salt water generator was switched off when the water temperature is too low for it to work. The pump was switched off too. This proved very successful and the water stayed in good condition with the bonus of saving some pump electricity.
The poster also did this in summer but I cannot believe that would work in our pool nor am I prepared to risk the illness and infection downside.
As to the filter being damaged - its full of gritty bits already. 
