My Philodendron: some leaves have brown spots what could this be?

Question

Lack of light and water or bugs?

Answer 1

It doesn't sound like bugs or water. Did you drip fertilizer on the leaves? How about when you water it--is it in the sun where the water could cause "burns" when the sunlight hit it?

If it's neither of these I would spray it with Neem Oil (Bonide makes a product called 3in1 Rx that is simply neem oil that is ready to use). Neem oil smothers insects it contacts and it also has fungicidal properties. They would cover both of the other things it might be. Call your local L & G center and ask if they have Bonide 3in1 Rx or any company's neem oil.