Acclimation process: Directly Into tank. He had one other (besides transport cup) since his venture into his 5 gallon tank. Before this tank he had a night in 1 liter tank.
This was probably the cause of his pale color and horizontal stress lines. Whenever you do a water change, or put him into new water, you need to introduce him to the new water slowly. To acclimate:
Take the temp of his current water. Then scoop him into a plastic cup with this same water in it.
Do your water change. Refill the tank with tap water that is the SAME temp as what's he is currently swimming in. Be sure to add the correct amount of the water conditioner!
Float his cup in the new water for about 15 minutes, so that you know the temp inside matches the temp in the bowl.
Add a SMALL amount of water from bowl into his cup. (Several tablespoons, or about an ounce.) Let him sit for 15 min.
Remove a small amount of water from his cup and discard it. Add another SMALL amount of water from the bowl. Let him sit for 15 min....
Repeat these steps for an hour or so.
Then gently release him into the new tank.
Do not rush this process!
What are the first three ingredients of the Wardley food? Fish Meal, Wheat Flour, Dehulled Soy Bean Meal. :/ Not good.
Twice a day, he gets: A few pellets, 3-5. He doesn't eat them to be quite honest, actually eats maybe 1. Spits them back out. He ate a few of the crums tonight after I had crushed the pellets but either spit most of them out or let them fall to the ground.
The two most recommended brands of food on this forum are New Life Spectrum (NLS) and Omega One Betta Buffet.
Also, you're overfeeding him. A betta's stomach is about the size of its eye. I'd suggest giving him just 2-3 pellets each time, for a total of about 4-5 per day. (My smallest guy gets 4 per day. My largest gets 6.)
Is the salt good for the slime disease or only fish rot or both?
The grey "slime disease" is very dark, almost black. I can only tell it's grey when I shine a flash light on him. Could it be a natural spotting?
Slime disease? Why do you think he has this? I think he looks fine, except for the rip in his tail fin. And that will heal in his warm, clean water.