Help what's this

This is burning caused by using bat guano and quite common when using bat guano. I have found that if your soil is generally healthy, quarter strength bat guano is all about what the plants can handle and certainly never more than half strength. I have always thought it a bit irresponsible of bat guano manufacturers to recommend the dilution rates that they do, obviously they base their dilution levels on soil that is very poor and has never had any other type of additional fertilizers added. The combination of guano and Big Fruits in this case has been way too rich and caused the burning. Unfortunately there will be no coming back for these leaves and you need to be be very sparing with any feeding in the next 2-3 weeks so that it does not cause further damage. Definitely half strength of your normal nutrients and no more guano for a month and only then at quarter strength. Anyone who follows me or is aware of my views regarding cannabis may be shocked by what I am about to write as I am hugely anti defoliation, but then again, they are not healthy green leaves. So........ I would however recommend cutting off the most badly burnt leaves (only), they will never recover and to leave them on the plant could lead to a fungal attack. It seems some leaves are already showing signs of attack, so removing them is your only option to stop it spreading further. I would also suggest just giving plain water until you can see the new growth is showing signs of recovery and there is no more burning occurring and when you do feel things have settled down, tread lightly and start with half strength nutrients weekly until you are confident they can handle a bit stronger feeding. Hope this helps,......... Organoman.