A bit too much yellow

I have 4 plants in a small indoor space. I am using a organic wormcasting based liquid fert blend. Lights include a 240 watt hps and 2 smaller low-heat lights, which complete the spectrum. They have been doin really great, now they are about 3 weeks into flowering and it seems that a little too much leaves are yellow then normal, including a few that are not bottom leaves. I am sure it is not a fert or ph problem. I think it is too much heat, or over watering. I have been keeping a closer eye to make sure that the soil is totally dry between waterings. Any suggestions? Or am I not thinking of something? :confused:

well.. to much heat is usually shown in the stems first.. they tend to change colour, usually go red.. you'd also notice an overall plant health degredation since to much heat WILL kill the plant. as will to much water.

pics! pics are needed for more help

I just checked the stems and there is indeed red coloring, I backed off the light, and gave them some more ventilation about 3 hours ago, and it seems to be clearing up a bit already :)

ps, ty for the tip

Rabblecron I think u need to do some reading on growing weed inddors cuz your doing several things wrong. I dont understand why u would use heat lamps as supplemental lighting..

You never want the soil to be totally dry between waterings, just when u notice the top layer of soil drying out a little, is it time to water.And are the liquid wormcastings the only fert uve been using because yellowing leaves can be a sign of nitrogen deficciency?

I use worm castings(N) in conjunction with bat(N), and peruvian sea bird guano(P), kelp(K), plus some synthetic Nutes too.