There was a nice women in the aquatic shop in Stafford, and i told her i was looking at filters for when i get my Axolotl and she was like yes i know about them, a women i meet at a car boot sale says she breeds them and uses an under gravel filter and i asked, but wouldn't sand go straight through it too? and the shop women said she uses gravel. I told her gravel was bad, and the women tried convincing me other wise saying this womens a breeder and she said gravel was fine. I just politely said to the women, well i have to say i believe otherwise and that i do chat on a forum where many of you say how bad gravel is, and i will believe them, she just went well fair enough.
Never feel pressured if your pet/aquatic shop keep telling you to buy gravel and your unsure/know its bad, just say I'll think about it or i don't believe it is. You've got to remember, they run a business, As far as most of them concerned (and I'm not meaning all) a sale, is a sale. They are making money from getting you to buy something.