HELP - First time grower in a crisis

[Mutangeroo]

Ok so this is my first time growing and I've made a number of mistakes along the way and am stuck in a situation where I may lose out on my 7 weeks of work.

Let me lay some groundwork. I am growing indoors since 24th November 2020, in a grow tent, with soil. 3 of my plants are regular light cycle plants and one is an autoflower. I have an extractor fan with a carbon filter running but I have suffered with keeping my temps up over the winter as my house is very cold.

My first problem was over watering, i think it stunted the auto and created a gnat issue in my tent. To solve the gnat issue i added and inch of sand to my pots and this seemed to help. I got too eager adding nutrients (using a miracle grow plant mix) about 4 weeks into veg and gave the auto what i think was nutrient burn. Its never recovered (see the picture of the worst looking plant with next to no growth)

i kept it going in the hope ig may recover. About 2 weeks ago switched to a 12/12 light cycle and I think I made the mistake of adding some extra nutrients to the other 3 after a pruning session and have slowly noticed the leaves discoloring and curling. I'm also noticing there is some really slow growth on my potential bud sites and I'm worried I've buggered the whole lot up.

Any ideas to save this please?! I'm doing a lot of guesswork here.

[Wolfe0420]

Use anything but miracle grow

[MeEasy]

Yes miracle grow is not a good food for weed it just doesn't like it at all. It also looks like you burned them with your lights. I think you would benefit greatly by reading this and you might save the two larger plants just as test subjects because I doubt if you're going to get anything to smoke from them but you could learn a little playing with them. A better option will probably be to read though this and start again.

https://www.growweedeasy.com/basics

[Rwise]

I'll agree with letting go of the MG, though I have heard they now have an organic line (have not looked), to me it leaves a taste/harshness behind that will not come out ever.
I can also agree with nute/light/heat issues, but,
And here I go again, whats the PH? Water, soil, feedings.

[Wolfe0420]

To be honest with the gnat issues and in their current state...IMO if u want to bud something out start over. WithNute burn it does start on the tips and creeps in. Visit your local grower supply store they would love ur business and be happy to help or even Amazon can get u some proper nutrients and if price is a issue you can make a compost at home that will be 1000x better than miracle grow. Your filter and fan combo should be keeping the pests away for most part. When watering the top of your soil should be dry for a few inches before next watering, roots love air and need it so letting them dry out for a bit isn’t going to kill them. My first crop was a big giant fail and the next few kept running into issues spider mites ect temp issues high humidity it was on and on and on just never give up because years later I’m dialed it and I’m smoking some of the best weed right now that I grew myself and one day you will too.