brown spots

All right here it goes i have a trinity strain i am a newbie i have cuttings in fox farm(ocean forest) soil and i am using fox farm nutes plants are just veging. They where doing great tell today when i noticed they are developing small brown spots on the leaves. The only thing that has been changed for there feeding schedule is the water i was using distilled and then i bought just drinking water on accident. Could the spots be PH stress or could there be another problem. I water roughly every 2 days giving them nutes everyother watering. Please someone help me out i can get some pics up shortly but the camera is kinda low quality.

It could very well be the water. Distilled and drinking water have different ph levels.

Pics would definately help

i wish the pic was better quality but you can see the brown spots on it.

Looks like a Magnesium deficiency. Get some epsom salt...