[Aero/Hydro] 25x Caramella

I think I have a problem, nitrogen deficiency or over watering the rockwool cubes. To correct this, I reduced the aeroponics watering cycle. Before I was doing 10 seconds watering cycles every 5 minutes. Now I water 10 seconds every 15 minutes. I will also increase the nitrogen fertilizer in the water and also monitor the ph properly. With the aeroponic system the ph level in the water tends to rise rapidly. I add ph down every time but I think I don't do it often enough. This could explain the nitrogen deficiencies.