Hydroponic gardening is soil-less gardening .. No soil !  However the plants need nutrients that are normally within the soil from which they grow.  All soil naturally contains basic essential plant nutrients, which is the very reason why Commercially available fertilizers do not contain all the nutrients a plant requires, it is anticipated the plants will attain these from the soil in which they are growing.

In the case of Hydroponic plants, there is no soil so naturally there are no soil borne nutrients hence commercial fertilizers prove inadequate. Hydroponic Nutrients are needed . Hydroponic Nutrients are fertilizers have been formulated specifically for Hydroponic systems, these Hydroponic Nutrients contain the essential elements that is nature would be in the soil.

Various plants require different proportions of Hydroponic nutrients at different times in their growth cycles.  Many Hydroponic nutrients are labeled as ‘grow’ or ‘bloom’ so that even a new grower will recognize these solutions easily.

Rotating your Hydroponic nutrients in accordance with plants growing cycle is another important factor.

The depletion of certain nutrient elements during various stages of the plants growth can be overcome if this is done properly.  Ideally you should change the solution every other week. The nutrient solution to water ratio must however remain consistent. Fertilizer levels  will increase with excessive evaporation and can cause extensive root damage.

 Hydroponic nutrient solutions are generally sold in a concentrated form. The grower must mix it according to manufacturers instructions and as per the requirement of the subject plant. For instance a weaker solution should be used for plants in poor growing conditions such as overheated gardens, low or poor lighting or just crowded plants. Newly planted cuttings will also initially benefit from a weaker solution.

  Normally growing and spaced healthy plants need a basic "normal" or regular solution . If your garden can handle high volume growth – has good lighting and ventilation and carbon dioxide production & circulation, you could probably use a stronger Hydroponic nutrients solution. It is advisable to experiment on a few plants first rather than burning out an entire crop.  Increasing the fertilizer concentration gradually will also reduce the chances of the plant burning up.