What kind of fertilizer can I use for greenhouse tomatoes?

I have some All Purpose Greenhouse fertilizer - is that OK?

For greenhouse tomatoes, buy a premixed soluble fertilizer formulated specifically for greenhouse tomatoes. An all purpose greenhouse fertilizer, i.e. 20-20-20, is a poor choice for tomatoes. Tomatoes need a grade with much lower nitrogen and much higher potassium, as well as several other essential elements.

These companies all make excellent fertilizer for greenhouse tomatoes. Follow the mixing instructions included with the bag:

Total Plant Industries
P.O. Box 805
Winnsboro, LA 71295
1-800-433-3055

Hydro-Gardens, Inc.
P.O. Box 25845
Colorado Springs, CO 80936-5845
1-888-693-0578

Growers Supply Center
3000 South Highway 77, Unit 214
Lynn Haven, FL 32444
850-785-8974