Duda Energy 1 Quart / 950ml 85% Food Grade Phosphoric Acid Rust Remover Clean Etch Metal

If you are still buying the pre-mixed 10% or 20% pH Down from the grow shop, you are literally paying for expensive water. I switched to Duda Energy’s 85% Food Grade Phosphoric Acid for my 100-gallon reservoirs, and the cost savings are insane. One gallon of this concentrate will last me as long as 5–8 cases of the 'brand name' stuff. It’s food-grade, so I don't have to worry about impurities messing with my root zones. It’s extremely clean and stable. Because it’s 85%, a little goes a long way—I only need a fraction of what I used to use to hit my target 5.8 pH. If you’re a high-volume cultivator, this is a no-brainer for your bottom line.

I use this to make a rust converting solution. It works great and since I dilute it myself I can make several batches from one gallon of concentrate.

Excellent product, very happy with the results. Duda Energy was great to work with, and they promptly answered my questions. I will definitely buy from them again!

We use this to make homemade soda in a soda machine. The phosphoric acid must be diluted to do that. We make 8 ounce bottles by using 1/8 of a cup of this and 7/8 of a cup of distilled water. This brings it down from 85 percent to much closer to 10 percent solution. We were buying 8 ounce bottle of Phosphoric Acid 10% Solution - 8 Ounce For Beer Making before that. Now we just fill those 8 oz bottles with our own dilution and it saves a lot of money. We also used this product to clean a calcium stains in sinks and toilets and to strip rust from steel. Leaving the product on bare steel for several hours also etches the metal and prepares it for painting. It also darkens the steel by leaving a metal phosphate coating which protects it from rust.

Bought as a last resort item. It performed in its unintended role with honors.

I wanted a chemical to dissolve rust and I was told that this would do the trick it does work but not as well as I expected I am happy with what it does may need several coats but it does work

This is a must for my hydroponics system. A far better way to decrease the pH than using pHdown products and much more economical as well. Between the high pH water in my area and the plant chemistry that drives it, I'm regularly adding a few ml of phosphoric acid to the system. Couldn't do without.

Diluted with water to remove rust and to Phosphate coat bare steel before painting.