GG#4 and Cheese in 2.6x2.6 tent

I started germinating my seeds by placing them in a glass of pHed de-ionised water for 20 hours. Once the medium was buffered (not too much), I took the seeds out and immediatly could see some root coming out, I must say I was impressed. I planted them directly in the medium and will spray some pHed water regularly. I just got the seeds on small pots and covered it with small plastic bags so it could keep the moisture for longer. I will uncover them once or twice a day to let them bread for a couple of minutes. I will keep the light off for about 18 hours now and will turn them on, at 65cm distance on the lowest setting. Now I'll just wait. I had one problem though, hope I could get some help with it. When I fed them the water had a 5.7 pH but the runoff was much higher, reaching 6.8, nearly 7 at times so I don't really know what to expect from it. Fingers crossed.