MAXTITE Oxalic Acid (2 Pack, 4lbs Total) 99.6% Pure - Metal & Wood Cleaning and Bleaching, Rust Removal (C2H2O4) - HDPE Container w/Resealable Child Resistant Cap

This product works perfect for removing oxidation from sidings on houses when mixed with warm water and some light scrubbing.

Oxalic Acid works exactly as described; I used this to brighten the pine wood on a 2 year old deck. I used Sodium Percarbonate (Oxygen Bleach) to clean the wood before applying the Oxalic Acid. Item arrived promptly, 2 days after I ordered it. Mixes well in a chemical sprayer with hot water. I used 1 Cup per gallon of hot water; this yields what I considered to be a mild-to-medium-strength batch of acid: it cleans effectively, but won't eat through your hand if you get a little bit on your skin. You go through this stuff faster than might think; I only have 2 cups of acid left after applying 1 treatment to my 330 sq. ft. deck (it's difficult to spray anything on the balusters without a fair amount of wastage). I guess my only gripe would be the price; I paid $25.95 (plus tax, free shipping with Prime) for two 2 pound containers, but it's significantly cheaper per ounce if you order a greater quantity (economy of scale). Separate from the price, the product itself, in my judgment, is top-notch.

works really good

When you buy this product for beekeeping you are getting a pure enough product to use in the control of Varoa Mites (a parasitic mite that effects honey bees). Though there are other uses for this, including the cleaning of aged and molded wood on homes and decks it is commercially viable for use for honey bee Verona mite control. Using a heating device that reaches over 400F very quickly turns this Oxalic Acid powder into Formic Acid Vapor which, when expanded into beehives, reduces the population of mites on your bees. Used as recommended (FDA recommends 1 gram per application) it does a mediocre to poor job. However when used in the dose that has been observed by the University of Florida’s beekeeping program, 4 grams for a large hive, it has been observed by scientists to have a more effective range in controlling up to 70% of Verona mites attached to honey bees. I would not recommend this dose as it is not recommended by the FDA but has been observed in broad spectrum scientific experiments to be the most effective dose for mite control. Use your best judgement according to the laws of your state. For application I recommend the best applicator you can afford. I made my own with 1” pipe capsule, drilling and tapping in two Diesel engine glow plugs and using a 12V Truck battery to operate it at temperature. The resulting Formic Acid Vapor is emitted from a small copper pipe into the bees hive within seconds. IF YOU DO THIS: PLEASE USE a Chemical Vapor Mask to protect your eyes and lungs. Make sure you cover both eyes, nose and mouth…Formic Acid is dangerous to breath in or to have blow back into your eyes and can cause chemical burns!

Soak that whole house water filter housing in warm water and a spoon of this and it'll be crystal clear, zero scrubbing.