congrats on the lights coming in! that sounds like a good amount light especially since i think you're surrounding the plant with beneficial light rather than just one source of light from above.

A completely healthy plant may not lose some of its lower leaves and you are correct there might have been some sort of deficiency as to your nutes. It sounds like a manganese defeciency or iron IIRC but I would still look it up I think there's a section here on the boards for that.

sound off on nutrient strengths and ph and more [updated for 2010] - The Garden's Cure

here's a link to a chart on uptake levels of nutrients at different pH ranges for both soil and hydro. You can see that there is not one perfect level that will uptake all nutrients. This is why many growers allow their ranges to fluctuate. From generally 5.5-6.5 in hydroponic use. However, it is not impossible for cannabis to survive at let's say a 6.3 constant pH level. i also have some gh nutes laying around and I see they do carry all the important macro and micro-nutrients. I couldn't account for differences in genetics as to what ranges are specifically taken up by them but the chart is a good reference point... i just don't know for certain but as for now I'm ok with that. So, depending on your system and your water source, specifically whether your ranges tend to drop or raise while feeding, will tell you how to let them adjust. Simply, if your pH tends to rise you'll start at 5.5 and let it rise to about 6.3 or the other way around if your water drops. That's not for everybody. People are going to have different reasons for pH level changing, like algae or improper dosing to waste/nute buildup . So, just think about things logically. Read your charts, know your pH and EC. Those are the best three rules I can think of for offering advice to others.

Check out the phosphorus scale, very important to producing buds and having a healthy plant. The absorbtion does not start until about 5.8!! So you may want to get a water dropper and manually change your pH throughout the week. I'd say let it sit at 5.5 for the first day (day and a half) after feeding and for the rest of the week let it be something like 6.0. Careful of feeding to much pH up or down, that's why I suggest a dropper it messes with your TDS.

I hope I explained it ok.
As far as the pictures go, it's happening to everyone, so no worries...
redaaron Reviewed by redaaron on . Plants are dieing, please help! Hydroponic DWC Setup Grown in rockwool with rocks on top(recently had algae on top of rock wool, thats why the rocks are on top, I think algae was raising my Ph to 8 every 12 hours or so... I recently cleaned and refilled added new nutes) Lights 18/6 5 24" fluorescent plant lights 1 18" fluorescent light 1 18" Blacklight ALL 3" From Plants Lights cooled by fans Fans on plants 3 Air pumps running on high 24/7 Rating: 5