Hey everyone. First time hydro grower. I'm been having some problems with my plants and haven't found the problem yet. Now it looks like they are going to bite the big one.
The symptoms started with some brown/copper spots on the lower leaves. They started near the middle of the leaf, in between the veins as a single brown/copper spot. It then quickly progresses into larger brown/copper areas. Eventually taking over the entire leaf. It started on the lower leaves and has been makeing its way up the plant. After a few days the leaves turn all brown and curl up with just a hint of green patches, brittle to the touch (in fact when I touched the leaf it crumbled).
I bought some Cal-Mag and used 50% strength and sprayed in on the leaves. Didn't help. I read some more and thought purhaps I miss diagnosed and maybe it was actually a K problem. So, once again I sprayed the leaves with a higher K and still nothing.
I have flushed the system to rid it of an salts that might be locking up the rockwool. Still no luck. I'm affraid they are dying. Please take a look at the pics and let me know what you think. The one on the left has always given me some problems, you can see it is a little weak. The one on the right was doing good until recently. Now it is becoming like the one on the left.
Please help with any suggestions. I'm using GH 3 part formula in a hydro drip system. Currently I'm using the vegitative formula on the back of the bottles (that's 3-parts Grow, 2 parts micro, and 1 part flora) at 50% strength. Started at 30% strength as the symptoms got worse I increased to 50% thinking it was getting enough. 400mh lamp about 20 inches away from the tops of the plants. My PH was at around 5.9-6.0 but after reading that K is absorbed at around a 5.2-5.6 I lowered my PH to around 5.4-5.5 hoping that it would absorb the K.