PH in bucket 4.5???

When I add water, I add at PH 5.8 by the chart on the drop bottle.

Today is the 1st time I have checked the PH in the actual bucket though, and the mixed solution in the bucket reads like 4.5!

I am not going to speculate on how this happened, I will just blame it on my brother... it was probably one of his stoner errors...

Anyways, I added 25 drops of PH UP to the bucket, and rechecked it. It still looks low to me. Does this sound reasonable? 10 drops per gallon to go from 4.5 to 5.0? If so, I will just add more drops...

I guess, I was wondering if the color from the nute solutions affects the color of the water for PH testing??? Cause my water is already in there..in there..in the bucket!!! Do I just add more drops???