Hey guys, I have recently (yesterday) encountered 2 problems! Firstly, i realised that there was some kinda white specks (small ones) at the bottom sides of my tank which contains a motoro and arowana. I then put my hand in to see what it was and along the 4 bottom sides of the tank was a thin layer of slime. Any idea what that is? I then did a good wash-up of my tank. Was that a good move? Secondly, when i woke up this morning, I found a long poo made by my motoro who has been feeding on small cat fishes. Here's a picture of it! What's wrong? Will I be losing it? :/ And when people say put salt into the water, are they referring to aquarium salt or household salt?
yeaaaaa! i know earthworms are good, that's what everyone tells me and I see it everywhere on the forum but the thing is that this dude here likes to play punk and doesn't eat them! 
and when i try to put them in and he doesn't eat them, my dad would scold me cos the worms will pollute the water :'(
everything seems normal. I think that you might need to get a better filter and the ray to be fed more. Just make sure u pick all of those stuff up wen u do a wc. Also I think u should change the diet of the ray. Is it live catfish or is it filleted and maybe frozen pre cuts? I think u should either try live worms (or frozen but rays sometimes do not except frozen worms) or a precut and filleted tillipia.