Comacus
Well-Known Member
I need some help with diagnosis and solutions. This is my first grow in SubCool's supersoil recipe. The plants were doing great until a couple weeks ago when I started to notice the new growth taking on a lime green color. It starts at the base of the leave and works out to the tips which remain green the longest.[HR][/HR] I filled the pots 1/3 pure supersoil, next 1/3 mixed 50/50 with base soil, and top 1/3 base soil only. My temps run about 74-76 F. I do not think it is a deficiency but seems to be more of a lock out.[HR][/HR] I am only using water that I ph to 6.4-6.8. I do suspect my Milwaukee meter was out of calibration, and have since upgraded to a Blue Labs pen ph meter. I have a low cost 2 probe soil ph meter that shows the soil ph above 7.0. I had thought the dolomite lime added to the super soil would buffer the soil and keep it at 7.0 but think it has risen above for some reason.[HR][/HR] The main problem is the top leaves yellowing. The problem is getting worse, and growth has slowed significantly. I am also starting to see a few leaves on the bottom now yellowing. I am only about 1 week into flower so if I don't figure this out I think it will significantly impact this run.[HR][/HR] Here is what I tried so far. A couple days ago I gave a little compost tea. This may have made things worse as the ph of the tea was about 8.0. Today when the yellowing on top was worse, and I also noticed a few lower leaves looked like they had phosphorus deficiency from lock out I sprayed them with a foliar spray of Cal Mg. My guess is this is a Calcium lockout due to high ph, and potentially a phosphorus lock out.[HR][/HR] I need help! What next, maybe a top dressing with some more lime? A top dressing with some more supersoil? Thank you for your help.[HR][/HR]