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 bought this to use as a rust converter and it works great! I diluted this (1 part acid, 4 parts water) and it converted the rust quickly and effectively. No complaints.

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!

Bottled in qt size , bought 4 for a gal size price , thankfully allowing a purchase in Kalifornia.

After using different products from my local pet stores, household and online, the water in my 300 gal. tank kept rising overnight from 7 to 9 while I wanted it at 8 then I heard about this product been sold on Amazon so I decided to give it a try and I'm really amazed with the results. Have to be very carefull though because it's pretty strong so you better use it with caution. I can see the happiness in my fishes faces and if they're happy, I'm happy.

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.

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.