- Jack's Nutrients 15-0-0 Part B Calcium Nitrate, 25lb | Part 2 of a 2-Part Sytem, Powdered, Water-Soluble Fertilizer for Calcium Uptake and Strong Leaf Growth, Liquid Feed

Hands down the best hydroponic fertilizer I have ever used!!!! This is like giving steroids to your pl!!! This will make them grow so quickly and produce more so long as you follow specific instructions! Very easy to use as long as you know how to measure!!! I’m a lifelong customer of this product!!!!

For the money you get a good supply of fertilizer that is easy to mix and is the best I have found. If you want healthy plants you will be more then happy using this.

I use this in my hydroponic gardens. I’ve tried other brands but honestly this is the only one I will use. It produces some amazing quality veggies and fruit.

Can’t go wrong with Jack’s 321 line of products as long as it’s mixed properly. Always thumbs up!

I've used this for years and its never disappointed.

This is all you need. I've spent years buying boutique nutrients and this has done just as good for a base at a much lower price point. Works well with any additives, like silica, microbes or carbs. Other liquid nutrients you are paying for the weight. Mix this yourself and save.

great product one of the best nutrients out therr

I started using the Jacks 321 formula in hydro and now use it in all my grows.