sorry double post

IGNORE

If you are talking about the General Hydroponics Maxi-Grow powder then yes I have used them. I find that it disolves easier in warm water. I think I usually used between 1/4 to 1/2 tsp per gallon of water for lettuce.
I have lately switched to the Flora-Magic since it is a more general purpose nutrient so that I don't need to buy separate grow and bloom formulas and I can therefore get a discount for buying in bulk.

No matter what type of garden that is grown plants need the samenutrients. The way these nutrients are supplied is the difference.For example, hydroponic planting requires a different method ofsupplying nutrients to plants than does the traditional soilplanting method.

In hydroponic gardening, the fertilizer that is given to plants hasall the nutrients that plants need. In soil gardening, thefertilizer used for plants does not contain all the nutrientsneeded, because some of them are in the soil. This is the biggestdifference, but nevertheless both methods of planting do not changethe type of nutrients that plants need, which are 16 major ones inall.

Some of the major nutrients that plants need are listed as follows:

Nitrogen: This nutrient helps promote the growth of new leaves onplants.
Phosphorous: Roots of plants mostly need this material to helpsupport the plant. In addition, this material helps aid the plantblooming process.
Potassium: This mineral helps build a plants immune system. Inaddition, Potassium also helps a plant to grow in extreme cold andheat.
Sulfur: This substance aids in giving leaves a rich dark greencolor.
Calcium: This nutrient along with phosphorous helps the roots ofplants to grow. It also aids in helping new shoots of plants togrow as well.
Magnesium: This is what helps produce the chlorophyll, thesubstance that gives plants its green color and helps the plant toabsorb sunlight in order to make food.
The above list of plant nutrients needed is commonly known asmacronutrients. The three most important of these is usuallythought of to be the Nitrogen, Phosphorous, and Potassium. However,all of these help aid in successful plant growth.

Here is a link that might be useful: Click here to find out more about Hydroponics