Fungus - Solution pleassse

Okay...this is my second plant and this time I took pH of the water when watering, which I didn't do on the first. I saw it was a little high so I decided to put coffee grounds on the top of the soil because I heard that was a good way to lower the pH organically. I did this when transporting to bigger pot, which I gave a good watering. I watered a 2nd time about 4-5 days later, it probably wasn't as dry as it should of been.

Now I have this very very small mold/fungus looking stuff on the top of the soil. I took a lot of the top layer away and am going to let it dry much better this time before another watering. Problem is my plants lower fan leaves are getting light green spots on them now. It hasn't spread to the top of the plant yet, but I'm worried that it will. I want to get this under control before it is too late. I have heard that using 1 part Hydrogen Peroxide and 3 parts water will help. Is this true? Do you think the coffee grounds helped create this fungus?

Btw, temps are at 70-80 and the humidity is about 50-70% (it lowers as the pot dries)

Thanks in advance

Another note:
Those leaves with the green spots are now drying up...

Well...didn't get any help, but I figured I would post what I have done for anyone who might be searching in the future.

Pretty sure it was a simple over watering that caused the fungus/mold to grow on the top soil which then went to the bottom fan leaves. I treated the plant with a Hydrogen Peroxide solution (1 and half teaspons of Hydrogen Peroxide to 1 cup of water), spraying it 3 different days along with the top soil. After seeing the leaves getting worse I decided to cut all the leaves off that were affected by the fungus.

After doing so, to help ensure I got the fungus under control I let my soil continue to dry out completely then I watered it with the same Hydrogen Peroxide solution mentioned above. I have yet to see anymore fungus and the plant didn't show any signs of suffering from losing its 8 biggest leaves, though I'm sure its budding has probably slowed a bit.

Also during all this I put an air purifier by my plant to ensure it wasn't something airborne.

Hopefully all is good again. Definitely going to sterilize my entire rig again before the next one and from now on and not be stupid on the watering.