Ti plant leaves have milky spots and streaks

Question

We do wait for chemical to weaken before watering with house hose

Answer 1

Can you include a photo? This sounds a bit like a few things.

Powdery mildew can appear as described, as could salt damage from chloroamine buildup among other salts present. These solids will not evaporate.

Downy mildew could be the culprit too, but this one may be more detrimental to your plant. A photo will help me to pin this down.

In the meantime, this article will help you with the proper care of these plants: https://www.gardeningknowhow.com/houseplants/ti-plant/growing-hawaiian-ti-plant-indoors.htm