I'm having Cardinal Tetras with a loach. Got one only because I've heard that they're aggresive if they're comfortable in the tank. That loach of mine will only come out from its cave and roam around whenever there's no one near. Once I approach the tank, it will run and hide again

A question, what has the water KH and PH got to do with the size od the SAE..just wondering. My other fishes are doing alright except for that SAE which i had noticed a huge difference in size.
Will check the water parameters later.
thanks dom