Illness/Sickness: Limb rot?

Here's some updates on my axolotl with hurt feet or limb rot..

first water parameters:
temp 19° C
ammonia 0
nitrate 0
General hardness in dh= 6 or 7 (translates to 70 to 125 ppm)
Carbonate hardness in dh = 1 or 2 (translates to 0 to 70 ppm)
PH = 7

I added an almond leaf to the tank 4 days ago, he's still shows the bloody fingers but today he doesn't have fungus..

The axie is acting normally, this is he's most of the time hanging around in his "dark corner" or in the cave or standing on his plants, and swimming a little around his tank, and eating normally (usually 1 red california earthworm a day), he's about 18 cm and I have it since december

Can I do something to adjust the hardness of the water? may this be the issue with the axie?

Here's some pictures:





his tank looks like this, it's 80x30 cm and 60 litres





thanks so much!

It does not look like limb rot. how old is he? I realize this post is old so how is your auxie doing?

Also you can buy water softner pillows that sit in the filter.