Im starting to have some problems with my plants

About 3 days ago a few of plants seemed like they were showing signs of nute deficiency because a few of the end of the leaves tip were yellow, only 1 or two, also the tones in the green just wasnt looking lush, now they are all pretty dark green. One of them even had 2 small holes in a fan leaf, and I dont have bugs so these things are definitely deteriorating from something else, I made a post about and people agreed I should add nutes, so I did I also started like half strength of there recommended "mild" dose

So I did and a day later they almost seemed a tad perkier, and today I can tell that there has been a little bit of growth there just noticeably a little bigger.

But now I am seeing some serious damage, leaves are starting pretty much burn, and crack, some look frail. I think I could have gave them too much nutrient when I did, and its not evem a chemical one its Earth Juice, suppose to be "non-burning" but im not blaming that here just saying, the plants are 24 days old now so I think they should be able to handle the nute but I may have just put too much in now because this really seems like nute burn.

Im using scotts potting soil, one of them are in a mix of tat and organic choice MG, one completely in organic choice MG, I know these have added nutes so thats why as soon as I saw signs of plant deterioration, it would be sufficient to give it nutrients.

My pH is 7, I use papers. So what should I do flush them? I will probably water them later today but should I add nutrient at all or what. Not all plants are as bad as others.

 

No none at all, I learned my lesson to wait from last time, I know it should be 3-4 weeks, and I was going to wait till 4 but then I saw a few holes and some leaf tips yellow. So I gave them a small solution. Actually now that I think of it, I even tested it on 2 plants, and after a day THOSE plants looked better, so I decided to give it to all.

My soil is that pre ferted stuff, time release stuff, I know the Organic MG had a longer nutrient release time span than the scotts. They both have good NPK's, I think the Organic more so.

I added about half a tablespoon of Earth Juice grow.

 

I will now work on getting a GOOD pH meter, I saw some decent ones for like 30-50$, but thats alot right now to drop on one thing, I mean I could add a fuck load of more lights for that price.

So should I flush the soil(2 gallons for every gallon in your pot I heard?), also do I need to do it all at once or can I take some time, and also will it be alright because I wont have time to distil the water and let the chlorine evaporate, so maybe I am better off just buying some distilled water? But regardless thats like.. 10$ or more worth of water, im a broke person right now.

And could it be the nute may have messed with the pH? Because I just dont understand how my plants seem to need it because there getting holes and just not looking as good, but then now there almost getting nutrient burned, maybe I just gave them a little too much but this isnt a chemical nutrient.

 

Bump, can someone please tell me how much water I will need to flush through my 3 gallon planters? And will it matter if there is chlorine in some of it or not, because I only can distill 2 gallons at a time.

Please someone, I really want to adress this problem quick.