Out White Brite Laundry Whitener, 28 oz

I recently moved to an area with hard water that contains a high iron content (found out after the fact). I've never had hard water so I didn't know I couldnt use bleach. I was so disappointed when I opened the dryer to find my load of whites had turned a sickly yellow-tan. I found Out White Brite after some Googling and decided to try it. The first time I used it I barely saw results, but I had used warm water. I tried again using HOT water and it worked wonders! I live in an apt with shared laundry and the machine doesnt have a pre-soak function, so these became white again without soaking. The key seems to be hot water. A white poly blend bralette snuck it the load and came out with a bluish tint, so Im guessing this product contains some type of bluing agent, which is fine by me, but be careful to use on cotton only clothes and linens.