I put this in my Rid O Rust tank and it keeps my vinyl fence and house trim along with the sidewalk and driveway from turning orange. Great product.

Works, although not as well as the previous product that was not quite a concentrated. My 10:1 dilution ratio does not work as well with this product, and neither does a 9:1--still leaves some light rust on house and driveway. I'll either have to use RR2 or go with less dilution with water to make this work.

Doesn't even compare to their old formula.

Back in April 2015, I ordered 8 gallons of the previous Rid O Rust Hard Water 2000 formula from Amazon.com. We have exceptionally hard well water, and it takes 8 gallons of this product in my 30 gallon tank to keep rust stains off the driveway. I paid $133.82 for those 8 gallons, or about $16.72 per gallon. Product worked as it always has.

In June 2016, I ordered 8 half-gallons of the new formula. Advertised as "twice as powerful as the old formula." For this added convenience of smaller bottles, I paid $162.62 or over 20% more. The result? Rust stains all over my mailbox, driveway, and sidewalk. The claim of being as effective as the old formula with 1/2 of the solution is just pure fiction.

Perhaps I should order 16 half-gallon bottles? 24? 36? I'll be looking elsewhere next spring when it's time to fill the tank again. I'm done with Rid O Rust.

Put in a drip system w/ a 30-gallon tank to cope with the iron problem and so far so good. It's not yet 100% but may get there in time, I hope. The installer recommended this brand and said not to use any others, which is fine by me as I have no interest in experimenting. The amount that should go into the tank will depend on the chem analysis of the water coming out of your well, which should be done before running the unit. Mine is not too bad so I can put in a 1/2 gallon bottle per 30 gallon tank. Mine has been set to consume about a gallon of fluid an hour, which translates into a drop in the level of fluid in the tank of about an inch an hour. Depending on how often you water, you can count on average on using one 1/2 gallon bottle of chemical a month, which beats the labor of removing the stains.

This new concentrated bottle of their old unconcentrated bottle doesn't work nearly as well. It's disappointing but the old bottle is no longer available. It costs more now to use than the non-cpncentrated version. When used as directed and even with extra, I now have the rust on my driveway.