You can use humic acid. The important things you should watch in hydroponics is pH, solubility and compatibility of the salts, and the concentrations. The vegetative growth depends of the nitrogen concentration. If you want generative growth, simply low the nitrogen concentration.

I suggest you prepare one gallon of your nutrient solution with humic acid, and observe it for at least 3 days. Test it under the sunlight too. If there is not precipitates, or changes in the pH then you can use it in your strawberries.