First of all, I have to apologize for not having any pictures. I haven't attempted to load any pics yet, but I would like to get some advice from some people who have grown a few crops before. I will begin with my setup and some specifications. I have a closet grow, with wall-to-wall reflective mylar, with dimensions of 4'W x 2.5'L x 6'H. I have a 600W MH approximately 24 inches from the top of the plants, a 400 CFL exhaust fan and a 190 CFM intake. I have some timers and other hardware in there but I won't mention everything because it is not related to my problem. My temperature during the light period stays between 75 - 85 degrees F at the extremes, but the average temperature is usually around 78 F. In the dark period, the temperatures drop to around 65 degrees F. My humidity is pretty steady between 48-52%, but I have seen it dip down to around 40% occasionally. I am growing in solless media; 50% sphagnum peat moss, 25% perlite and 25% vermiculite and about 1/2 teaspoon of dolomitic lime. My plants are each in a party cup(12 ounces I think). This is day 11 of my grow and I have been having problems since around day 5. My seed sprouted out of the soil of day 2 and I gave her a good watering on day three. I have heard that first time growers usually make the mistake of over-watering so I made sure to check deep into the soil with my finger to make sure it was dry. On day 5, the soil was really dry so I gave her a second watering. Up until this point everything was bright green, healthy and reaching for the light. The growth was slower than I expected, but I just figured that's because I am a new grower and I don't know what the hell I'm doing. I check on them the next day and two of them (out of three) are getting yellow tips. So me being the noob that I am and only going off what I have read, I assume that this is obviously over-watering. Well I have went 6 days without watering and still no changes. I have actually posted this problem on two other threads and every person told me it is over-watering. I know I am a brand new grower, but there is no way in hell that they are over-watered. I have been so careful not to over water them that I would have allowed a slight under-watering just so I didn't drown them. I finally broke down and watered them last night because the soil became so flaky that I was 100% sure these girls did not have too much water. This is now the next day and I don't see any difference in their status. They are not getting better, but luckily they are not getting worse. They have been pretty much the same for nearly a week now. Now I have already been flamed and been treated disrespectfully for asking such a beginners question like this, but I think this is a legitimate question and I would really appreciate a real solution to this problem. There are only a few factors I need to worry about; light, water, air, ph and temperature so I don't see where I'm going wrong. Assuming it's not over-watering, which I'm 99.9% sure it is not, is it time to give nutrients already on day 11? Of all of the things I have read on forums, in articles and what I've seen in videos, it seems that yellowing tips are associated with over-watering, nutrient deficiency or both.
I also forgot to mention that growth stopped around day 5 and the plants are only about 2 inches in height at best. I know that there is probably a lot of root growth going on underneath the medium, but 2 inches seems ridiculously short for their age. I also didn't specify this, but the yellow tips have never become crispy or brittle at any time. Other than the yellowing, they still look well hydrated and are definitely alive.