s310t, new sand

[swimdaddy]

Sand will never wear out, it is the same today as the day it was put in your filter. With good pool care, you shouldn't need to replace it. In fact, sand filters work better as they trap particulates that "fill in" the spaces between grains, so they can filter smaller particles than fresh clean sand (unless you pump is too big, pushing everything through). That is probably why your sand was more compact as you dug deeper, which may be a good thing.

That being said, if you are having trouble with filtration and you don't kow where your sand came from, I would replace it. I have heard of putting gravel on the bottom, but I am not sure that would help. Sand would just work its way in between the rocks and around the laterals anyway. I think some manufacturers may say to do this, would check with your filter's manufacturer. Maybe someone else has more info on this.

[Anonymous [GDPR] European in the UK]

Now you should follow the manufacturers advice or risk any warranty issues, Blah blah blah. Without any information on your system in your signature advice is tricky, some suppliers do say gravel over the laterals as it does help to diffuse the backwash but from my experience most filters backwash isn't all that good leaving plenty of dirt remaining behind in areas where the water doesn't reach. The Hayward S310t seems to be just sand and not gravel.

Sand is in use in lots of filters around the world but I am not using it any more as there are better alternatives, yest it's really cheap but it can be bettered but there isn't much point in fitting anything else unless you have the correct flow for the size of your filter and that is probably slower than what you have now as slower filtration is better filtration. The pool industry generally feels that faster is better but that's up to them and of course up to you.