Hi to all. I've recently bought an Axolotl (yet to be named, so any suggestions would be appreciated

) & am trying to establish what is the best type of material to have on the tank bottom. I've spent quite a while looking on the net only to get more confused - some people say sand, others say rock, but others say that they swallow sand & that it builds up in the axolotl over time, but rocks are hard to keep clean. I only want what's best for the little guy, so any suggestions would be really appreciated.
I originally tried sand, but found that the tank water was hazzy, so I've now got a mix of big river rocks & big marbles - the water is still hazzy but this may be due to bits of food that I haven't been able to locate that he hasn't eaten....
I'm also unsure if he is actually eating, he's not interested when I dangle food in front of him & I've given him a few Axolotl pellets too but don't really know if he's eaten them, should I be worried?

Any suggestion on feeding would be greatly appreciated also....