Actually there is nothing wrong with GH 3-part I have had great results in the past. You said half a tsp per 2 1/2 gals water? Thats way below half strength but good for lil ones. By rights u should not have to give ur babies any nutes till their 3rd to 4th set of "true" leaves appear. Full strength on GH would be more like 5ml of each part per gal of water. 5 ml = 1 teaspoon. Biggest thing is dont try and rush them. I use to start mine in Rapid Rooters and then put in 16oz plastic cups with holes poked for drainage and fill with Tron. Hand water till ready to put in whatever system u using. The water solution I used was water, clonex solution and GH Subculture for root growth. Just that will take them to nutes. I would water mine 3 times a day.