Greenway Biotech Calcium Nitrate Solution Grade 15.5-0-0 Fertilizer Contains 15.5% Nitrogen & 19% Calcium for Tomatoes, Plants- Water Soluble Hydroponics Fertilizers for Vegetables- 2 Pounds

Extremely high purity. Uniform and universal color that is as white as fresh snow. Dissolves exceedingly quickly. Very small spheres approximately <1 mm to 3 mm in diameter make it easy to weigh out extremely precise amounts for hydroponic plant home recipes.* I am growing tomatoes and lettuce myself. Personally I make use of recipes by Dr. Howard Resh, whose books are available here on Amazon from CRC Press, and who also has a website with more limited information offered. (I recommend the books. I do not provide the website link here because that is not allowed according to the Amazon review guidelines.) While using ceramic metal halide lighting, and using this product to formulate the recipes cited, my indoor winter tomatoes have turned out amazing!I tried this brand first, then decided to order an alternate brand to determine if it was the same or at least as good. The alternate brand was inferior: 5 mm to 7 mm spheres, non uniform color (many dark / strange outliers), and the average color was a light-tan. In the future I will purchase only this brand as long as it is available on Amazon. I will add pictures of both to this review over the weekend.Oh, and as a "tip" to those mixing hydroponic nutrients at home, regardless the crop. USE ONLY COLD TAP WATER, and only after flushing the line/faucet for sufficient time. The reason? In my case I have a tank water heater setup. My water heater had been replaced recently. I also have in-floor radiant heating. Those lines are plumbed from the same tank. (Not sure if that is to code, but they are.) This means that my hot water in the winter-time tends to have enough NON-CHELATED IRON (aka RUST) in it to be visibly slightly brown at the beginning of the season. Even after that passes, there is enough non-chelated iron in the water to cause nutrients to fall out of solution. When this happens, a very non-soluble precipitate forms on the sides and bottom of the bucket. I quickly discovered that this can be easily be cleaned off after disposing the failed solution by using soap and water. Without using soap soap, it is as rough as a truck-bed lining, and laughs at water rinsing. So... learn from my lesson if you happen to be a novice in hydroponics. Use only cold tap water. Since temperature can influence solubility, it is often advisable to let the water sit in buckets overnight before making your recipe. If I am impatient, I'll boil cold tap water in a well-rinsed electric kettle, and then add that (1.5 L, one kettle worth of) now-boiling from-cold tap to 4 gallons of ice-cold tap to get to nearly room temp in a hurry.* I use two small scales that I purchased on Amazon when measuring dry nutrients such as this: Search Amazon for ASIN (Amazon stock number) "B0012LOQUQ" for up to 100 g samples at 0.01 g accuracy. The other scale I use ASIN "B0012N1NAA" for up to 1000 g samples at 0.1 g accuracy.

Put it on tomato plants in the evening and definitely saw an improved difference the next morning.

NO LUMPS.

Growing beautiful green

delivery as promised. Have not used yet. Will start using in early may as a water soluble mix for garden plants. This will give me the ability to control the amount of nitrate i feed plants.

I like that the product readily dissolves in water. I followed the recommended dose and I have not burned my plants. My plants love this stuff especially my lettuce, pak Choi, and strawberries.

I'm not sure if it is normal but there is a fine powder left at the bottom of the tank. I never notice until I had to empty the hydroponic reservoir out a whole lot of white powder still left there so most of the Calcium isn't water soluble. Maybe this is normal my water ph is 5.6-6.5. The Calcium powder is extremely fine it is fine enough to get carry by the water until settle.

Good stuff. I dissolve it separately before adding to my main plant water feeding reservoir, otherwise, you could have a chemical reaction that makes complete dissolving of the product difficult if not impossible. Because of our heat here in the desert, I put it in a water bottle, fill with water, shake until dissolved, then freeze. When I am ready to use, I then float them in the water to cool the tank down before adding to the solution thereby serving a double duty. Be sure to keep it in an air tight storage if you have high humidity because calcium nitrate will clump with moisture.When feeding your veggies such as tomatoes, feed 2 parts calcium nitrate to 1 part epsom salts for proper plant uptake and usage. I use 12 grams calcium nitrate, 6 grams epsom salts and 5 gallons of water. Be sure to mix each separately and dilute each before adding to the water solution for best results. I use that solution every day for watering and they just love it. Branches of the tomatoes feel like tree branches they are so strong.