Alliance Chemical - Hydrochloric Acid 31% (31% HCl) - Technical Grade (20 BE) - 2 Quart Bottles - 64 FL Oz - Strong Acid for Industrial Use

31% works perfect for my uses.

I bought this product to finish the removal of hard water rust deposits in my toilet bowel. It worked very well, but note my caution about how to deal with the chlorine fumes it produces.I initially used ZEP Acidic Toilet Bowl Cleaner. I emptied the bowl (not the tank) using a small electric pump and then poured in about 2 cups of ZEP. I let it sit for 15 minutes and then used a toilet brush to remove the rust deposits in the bowl and around the rim. This removed most of the rust but some thick stubborn bits remained in several small recessed areas. The ZEP product contains 10% hydrochloric acid. I reasoned that I needed something stronger and found this product containing 30% HCl. It is somewhat pricey but I was determined to finish the job. I emptied the bowl, as before, and poured 2 cups into the bowel. I let it sit 20 minutes and, wearing heavy rubber gloves, used a Brushtech Flexible Drain Brush (22" long, bristle head 1.25" diameter and length) to scrub the small recesses in the bowl where heavy rust deposits remained. Because this product is so strong, it produced chlorine fumes that irritated my lungs. Fortunately, I had on hand a North half-face respirator mask (model N7700-30, comes in 3 sizes, S,M,L) and filter cartridges for HCl and Cl gas (N7500-3). If you don't have this gear, you will need to use a big fan to properly ventilate your work area. After the scrubbing, I flushed the toilet 5 times to remove the acid and then used my bare hands and a Scotch-Brite scour pad to get at the recesses containing the now-softened rust deposits. This finished the job -- my toilet bowel is now rust-free.

Works great, The Price is Right

Once you understand and are careful It will clean the toilet and save the day!

I use this hydrochloric acid with Sodium Chlorite, 80% Flakes, to make Chloreene-dye-ox-hide. The result is an excellent solution.

Easily dilutable to 4% concentration

This was recommended to me and it's just what I needed.

It is as advertised