4 x 1000 ml (More Than One Gallon) 4 Liters Phosphoric Acid 85% Food Grade, Rust Remover, pH Down - High Purity Phos Acid - More Than 4 Quarts - Made in The USA

I used this product to neutralize some charcoal produced from burning dead brush and small branches before using it to fertilize raised bed gardens. To make the char, I put my fire out with water as soon as the wood was burned down to a bed of coals and stirred it while spraying until smoke stopped entirely. Char is a great additive to soil, but is much too alkaline without neutralization. The phosphoric acid neutralizes the potash and produces a nice neutral buffer containing both K and P in balance for fertilizing. Experimenting while using a pH meter, it takes about 4 ounces of phosphoric acid for 10 pounds of charcoal to neutralize it. The char binds to the potassium and phosphate ions and helps soil to retain the nutrients longer. I also use sulfur to neutralize alkaline pH from char, and this helps with soil structure as well. Being food grade, this product can be used without concern for toxins accumulating in the garden the way aluminum sulfate can.

I like to use H3PO4 to remove rust and it works well and is safe to use. Interestingly, at least to me, is the need for it to come in a container that lasts. I purchased the acid from a competitor and used part. Several months later I decided to use some more. I picked the container up and the top tore off like paper. Wasted about half a gallon. Made the purchase real expensive and cleaning up the mess was not fun. Moral of the story, make sure the container the vendor uses is safe for storage of the acid. I believe the product reviewed is stored in HDPE. But to be super safe get a gallon glass jug.

I use to make my own ph down and it works fine. 7:1 ratio with H2O. Quality bottles and packaging was VERY secure. I have zero complaints. Review wants to know how many stars for flavor. I give it 5 stars. 85% phosphoric acid tastes like lightning. lol. In all seriousness, great product and I would repurchase if I need more. Please do not taste.

When I ordered this 4 pack of phosphoric acid the price was approx $48. This 4 pack of 1 liter bottles is a larger quantity than the other 1 gallon jugs and cheaper. The box arrived with the 1 liter bottles wrapped in absorbent towels and bagged in pairs...so two bottles were in each bag that was securely tied closed. Excellent packing, zero bottles leaked or were damaged and a good price for high purity USA made phosphoric acid = 5 Stars!

Works excellent as a derusting agent on steel and cast iron. A must have for people restoring cars.

You get 4 bottles of acid with composition to more than gallon. BEST PRICE ANYWHERE. I USE full strength then 2vdays drying then paint do not wipe off or wash off just paint over rust with gloss rustoleum and keeps rust at bay.

Got lime buldup? Rust? Tired of paying big money for weak products? This is the answer. This is the real deal...a quarter cup of this in a heavily lime/calcium buildup toilet bowl DISINTEGRATES the problem in minutes. Got an old crud-filled brass radiator? Mix up a couple gallons of water and jug of this stuff and fill up the radiator. It'll be like new within an hour. Not recommended for aluminum; don't think that would end well.

Guess they don't put a picture of the back label of the bottle on Amazon for a reason. It is not food grade. The back label says Electronic Grade- Industrial Use Only. Exceeds food grade sec doesn't help me if it is not food grade. I must say I am very frustrated. It sucks that you can't trust companies that say American Made and they are not honest.