Hi mickie_mouse, welcome. {{gwi:998412}}

I'm sure your US mates can tell you where to get the nutrient powders. I'm from Africa, and I make my own. It's not too difficult once you know what.

Otherwise . . . go to a nursery and speak to the experts.

Have fun

Short Answer: Yes people have tried. It does not work (for extended periods) becasue typical N-P-K fertilizer lacks the micronutrients required to sustain plant life.

Long Answer: A google search will offer more information than you ever wanted about plant nutrients as they relate to hydroponic culture.

Called Miracle Gro - according to them it doesn't work well because soil actually supplies some of the micro nutrients required - which are not in the water soluable formulas. It was worth a try!

The main difference between hydro and soil fertilizers is the nitrogen source. Ideally, only calcium and potassium nitrate are used in hydro, where soil fertilizer often uses urea and ammonium based nitrogen. The urea requires a soil orgainsm that does not exist in a hydro system to convert to a usable product. The ammonium nitrogen can cause root damage if too much is used. It seems to work OK with up to 15% of the nitrogen source. Ammonia nitrogen can be used in moderate amounts to bring a high PH down.

I haven't grown tomatoes, but used to grow herbs using a dilute miracle grow - epsom salt solution. Never had any problems with anything other that leaf tip burn and that was because I wasn't testing the EC(at the time).
I've also, on occassion, included liquid fertilizer for african violets as it contains the neccessary micro nutrients.
Hydro fertlizers aren't really that expensive over time, just a bit much up front. I have quart sizes of the 3 required by general hydroponics. I've grown four or five crops of singular plants and have barely dented the bottles.