Hello! I'm new (ignore the date it says on my profile, I only recently started really playing) and I've seen the thing about Genetic Philters and I think I understand them. So I was interested in buying some to see what traits my tamed pets carry, but I can't figure out where to buy them. Please help! (And thank you!)

For revealing carries/hiddens, you need a test kit. An unlimited version is available from the diamond shop (1500 dias normally, 1000 when there's a sale). But you can also look for people willing to test for free.

Other philters include things like mutators, dyes, prismas (only used at hatching), nulls, etc. These can be bought from the diamond shop, the scale shop, or sometimes from other players on the trade broker. They all do different stuff to affect pets.