Potassium dihydrogen phosphate has a high value in agricultural production, and its appearance is very similar to magnesium sulfate, industrial waste salt, ammonium carbonate, hormones and so on. This gives some illegal vendors a chance to make counterfeit sales. Identifying and purchasing real potassium dihydrogen phosphate is the basis of guaranteeing the effect.

　　1、上：正規的磷酸二氫鉀200克售價在6-7元左右，市面上售價在4元以內的有的甚是2元左右，顯然是假貨。

　　1. Price: The regular price of potassium dihydrogen phosphate 200 grams is about 6-7 yuan, and the market price is less than 4 yuan or even about 2 yuan, which is obviously a fake.

　　2、看包裝：包裝上會有醒目的“磷酸二氫鉀”字樣，執行標準為HG2321~92，總養分含量≥86%，其中P2O5≥52%，K2O≥34%。沒有其他諸如“Ⅰ型、Ⅱ型、真品、微量元素、復合型、改進型”等字樣，如此這般均可視為假貨。

　　2. Look at the packaging: There will be a striking word "potassium dihydrogen phosphate" on the packaging. The implementation standard is HG2321-92. The total nutrient content is over 86%, of which P2O5 is over 52%, K2O is over 34%. There are no other words such as "Type I, Type II, genuine products, trace elements, compound, improved" and so on, which can be regarded as fake.

　　3、聞氣味：真正的磷酸二氫鉀是白色無味晶體，能聞到味道的都是假貨，經過火燒、暴曬也無味道，有異味的說明是添加了激素或是假貨。

　　3. Smell: Real potassium dihydrogen phosphate is a white tasteless crystal, which smells fake. After burning and exposure, it is tasteless. The odorous description is adding hormones or fake.

　　4、嘗味道：真正的磷酸二氫鉀是淡淡的咸味，取幾顆放在嘴里，如果苦味可能是硫酸鎂，如果很咸，可能是海鹽冒充。

　　4. Taste: Real potassium dihydrogen phosphate is slightly salty. Take a few pills and put them in your mouth. If the bitterness may be magnesium sulfate, if it is very salty, it may be sea salt.

　　5、用火燒：取少量磷酸二氫鉀放在鐵片上，如果溶解成透明液體，冷卻后凝固成半透明狀物體，則是真品。

　　5. Burn with fire: Take a small amount of potassium dihydrogen phosphate and put it on the iron sheet. If it dissolves into a transparent liquid and solidifies into a translucent object after cooling, it is the real product.

　　6、水溶法：將純堿放入磷酸二氫鉀溶液中，如果出現大量氣泡則為正品，如出現絮狀沉淀則為假貨。

　　6. Water-soluble method: Put soda into potassium dihydrogen phosphate solution, if there are a large number of bubbles, it is genuine, if there is flocculent precipitation, it is fake.