I’m going to try to keep this brief and to the point.
I’m on my 2nd grow and I changed a couple of things and this grow is basically just about over because everything is going to die before it makes it to harvest. Before I get going on my next grow, I want to make sure I’ve properly diagnosed the problems so I don’t run into this stuff again.
Things I changed this grow from last grow: 3 gallon pots instead of 5, no silica supplement, used cal/mag plus from day 1, used Recharge from day 1, started in solo cups and transferred at 2 weeks to FFOF, waited ~1 month to add any nutes besides cal/mag.
Basically my assessment is that the soil (FFOF) became too acidic and I tried to bring the pH back up by adjusting the pH of the water going in. I’m pretty sure I’m seeing deficiencies of calcium and phosphorous on most of the plants and couple of plants are showing some nitrogen/sulfur issues. It’s all very confusing though because for the most part the deficiencies are happening from the top down.
A week ago I got some pulverized dolomite lime and top dressed that at 1 tbsp per gallon of soil. Run off pH is now between 6.4 and 6.6 for all plants except one that is stuck at 5.8. Before that all run off from all plants was 5.8ish.
Now I’m just trying to figure out how my soil became acidic or why the first time I grew, this same strain didn’t mind the acidic soil. The problems began when I saw yellow tips (~day 30 of growth) which were actually light burn. I thought the tips were an indication that they were hungry so I started feeding at half strength and started feeding the cal/mag at full strength (Botanicare Cal/Mag Plus) because every plant last grow had magnesium issues and I wanted to make sure that didn’t happen. I did two feedings at about 300-400 ppm and the first time I measured run off it came out around 1500-2000 ppm on every pot. I was extremely confused by this so I flushed all plants except 1, because science. Believe it or not, the only plant I haven’t flushed at this point is actually the healthiest as far as how much bud it’s producing.
As I’ve been trying to figure out just what the hell is going on I stumbled across the fact that Cal/Mag Plus has iron in it and I know the stuff in Recharge makes it easier for the roots to absorb iron, especially if the soil pH is low. The problems I’m seeing kind of resemble what looks like an iron excess, but I just don’t have enough experience to say for certain why everything ended up in this state. Do you guys think iron is locking out phosphorous and calcium or am I way off?
I greatly appreciate any help and advice. This grow has really tested my mettle but I’m not giving up. I’m sure I’ve left out some vital details so if there’s any information that can help just let me know and I’ll provide what I can. Thanks again!