How often to give nutes?

I mixed up some nutes the other day, 20-20-20 Gro-Terra at 1/4 strength (1/2 tsp in 1 gallon of water). how often should I water with this formula? Is it safe every other day? I know you guys can't give me an extremely accurate answer because all plants are different, but I don't want to burn.

The two plants are under CFLs, near 1ft tall, each having around 9 nodes if I remember right. I will test the soil tomorrow for it's N-P-K levels, along with pH it again.

I need some honest info on nutes though, everyone tells me that the plants can take up to quadruple strength nutes in one feeding if I have gradually increased over time. It says only water with nutes every two weeks though? Yet people water with nutes every few days? I am kind of clueless to all this really, all I know is nute burn isn't good and I've probably been avoiding it by barely feeding my plants.

Also, the color of the plant means what? Like darker green verse lighter green? I know the color varies strain to strain, but darker leaves mean healthier plant right? If that is the case my plants are really healthy, the leaves are a very deep green.

deep shiny green color is all good man. are they on veg still or you on bloom now. only people say flower them wen there a foot tall if you don't want tall plants(or that might be wat you want). have you only just started using nuits? i mixed up 25 L of water with my bloom nutrients in a big water bucket thing with a small screw up lid on it. i purchased a small tap and put it on the bottom,just left it in the room where i was growing and just fed them as and wen they needed watering.it lasted ages but i must have used bout 75L of water for TWO plants in soil just in the flowering period which was about 2-3 months... didn't stick to any set times like every 3 days or once a week etc.

also remember that if you use a water tank/resovouir,use a tropical fish air pump and keep all water n nutes aerated helps plant to take on board all the good stuff!!!