Mid-Late flowering deficiency or tox ? + MH extra UVB ?

Gentlemen and Ladies.

Got some ladies going through a tough time in the last two weeks. Need some knowledge!

Details:
- 6-7 weeks in flowering
- Miracle Grow Potting Soil (I know not the best)
- 3 Gal pots
- Water 2x a week - just H20
- Bubblicious, White Widow, AK-48
- 600w HPS

So any thoughts on what is going on and how I can correct it?

Also, I've been reading about switching you HPS to MH in the last 2 weeks of flowering to increase your UVB which will increase THC production.. anyone have experience with that?

Thanks for the help!

MG soil tends to be hot stuff loaded with fert. try a different soil next time. it's too late now for this one, except you could give a nothing but water flush until harvest.

polishpollack said:

MG soil tends to be hot stuff loaded with fert. try a different soil next time. it's too late now for this one, except you could give a nothing but water flush until harvest.

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Thanks! So you think that is nute burn?

looks like it could be a magnesium deficiency but its hard to tell from the pics

why does it seem like 1/2 or more of these "help somthings wrong" threads involve Miracle Grow soil?

what I have done in the past, and you may want to do it in the future, is get a pot with really good drainage and put a garden hose into the top of it and just leave it running for a while, it doesn't make miracle gro turn into magic but it helps to dilute the nutes that are pre mixed at least when you flush them out. obviously this is a last resort if you absolutely HAVE to use MG, but it seems to help. You can always keep the water for foliar spraying or something later on if need be. Anyways, just in case it will help you, I have been using this chart for a while now and it has helped tremendously, so have a look:

a lot of people like to think that mg deficiency is the cause of yellowing, but plants can turn yellow for a variety of reasons. the reason why MG soil is in so many "need help" threads is because it's loaded with ferts. it seems like this kind of plants doesn't tolerate MG soil well. It is designed to provide fert for a long time, too long really for this plant in my opinion.

You're correct on that, I've been fortunate and had decent luck with MG Organic Choice. I prefer to just water without bites for a little while she I first start using it though.