Stunted growth

Hello everyone , i am a noob but i try to learn as much as i can and want to learn more and get tips, My setup 300 watt cfl dual spectrum mammoth lite 40x40x120 VKO100 fan , Carbon filter ventilation , Now i have 1 auto speed bud and 2 auto sweet tooths in the tent females , the problem is i had like 8 ph or more at start so i bought ph- and control it at 6.5 ph when i water , they look healthy and very fresh but for some reason they stop grow they are like 10 - 12 cm above the soil , i use the gold label special mix soil , good ventilation in my room i have the window open and the temp is 22 - 24 . please help me anyone i threw 3 off my previous plants becouse of this and i am clueless , the sweet tooths are 15 days , and the auto sp bud is 6 days . Sorry for my bad english hope you understand what i write thanks. 3-4 cm from lamp on a 24/0 cycle . And the 3 other plants i had before grew a little bit more until they stop growing it was 1 northern lights auto fem 1 fem jack herrer and 3 auto sweet tooths in same pot.

Your water ph is not nearly as important as your soil ph. The soil will quickly buffer your water ph to that of the soil. So you can ph your water to whatever amount you want but it won't matter if soil ph sucks.

Ahh i see thanks for your reply man , I use Gold label special mix from netherlands apparantly one of the best soils , i dont know this its just what i got told , So i just checked the 3 plants 2 who are 15 days old have ph of 7,8 thoes are totaly stunned for 1-2 days , the one who is 5 days old in an much larger pot have an ph of 6.5 .

I was thinking of mixing water + soil nutes and get ph to 6.5 and pour it down thoes 2 with an ph of 7.8 is this a bad idea should i give it a go , any other tips ?

one of the leaves have turned brown/yellow on one of the lower leaves on the edge of it , no one else are like this and i did not give them anything but water and last 3 days with water with ph level of 6.5

Well...I can't really give you specific advice on limited info, a picture would help a lot. Also, I'm not a fan of autos so I'm not the best to give you advice on how to set them up for success better next time. I hear transplanting is not advised with them, but the few I grew I transplanted per my normal routine and they did fine.

As I said earlier, you need to know your soil ph. If it isn't in a fairly defined range in the mid 6's, you are wasting your time with it. So do a simple ph test on it. Here's how: Take a cup of your dirt and put it in a bowl. Add enough water (preferably in the 6-7 ph range) and mix it up good. Then let it settle for about 10 minutes until the water on top is clear (you may have to scoop out floating perlite). Then run your ph test on some of the clear water off the top and that will give you some idea of your soil ph. I send soil samples out for testing which gives a more precise answer.

The key to starting mj healthy is to understand the nutrient needs. As seedlings they do best in a seedling soil, which has practically no nutes in it. The plant has all it needs for the first week or two. I start mine in seedling trays with seedling soil and then layer on a little earth worm castings at day 10. I then transplant at 2 weeks from popping into solo cups that are mixed up half seedling soil, half hot soil. After two more weeks I transplant into gallon pots with full hot soil.

When you give a seedling full hot soil to start, you are much more apt to run into problems of the sort you describe, so that may be your issue. So easing your plants into higher nutrient ranges is strongly encouraged to keep them healthy. Good luck to you!

Okey i will defently try out the soil/water ph test later , yea i found out that aswell about transplanting autos , so the problem lies within the soil , i need to control the ph in soil and water , and feed them when they need , i must succed with this it is my top goal right now thank you again for your reply and time very good information .

Hey man i just did the test u told me to do , but instead of ph 6.5 i used ph at 6 , i tested after 10 minutes and after 20 again , on 10 minutes the ph was at 7.9 on the top of the soil/water on bottom it was 7.5 , on 20 minutes at top 8.2 ph on bottom 7.7 , and i used 2 diffrent soils Gold label mix and gold label special mix i did 2 tests on 2 diffrent soils the one who came out with lowest ph was the special mix , man i will go in to a wall soon i have been trying this for 2 months soon what am i doing wrong ....

Holy ... i just did another test this time i wanted to experiment abit so i used water with a ph of 3 and the bitchin soil is at 7 ... like is that even normal ?

What are you using for your ph tests, drops/strips/probes?

I use this one http://www.professionalgrow.se/no/ph-og-ec/fuktighet-og-ph-meter.html

Those probes are subject to pretty big variations between testings, and that solution you mixed up is known to have a ph difference between the top clear liquid and the bottom sludge. You can also have calibration error if you have not calibrated it. So all that considered, you soil ph is probably ok to a touch high. There are ways to lower ph, like adding compost, but I am not sure you have accurate enough info on your soil yet to make changes. Post some pics if you really want some help, hard to know what is going on otherwise.

I see think i understand , Yes i know before i posted here i was unsure without a camera its pretty damn hard for anyone to know , tomorow i will fix pictures and post up sorry for that ..

Sorry i had to take pictures in a hurry i barrow it from a friend . the one with little yellow leafes ontop is 17 days the other one with dots on the leaves are 15 days and the little one is 8 days.

the yellowish came after i changed ph , and growth has been stunned on both for 4 days now

the little one grows but slow ... it seems like in some days the grow very much then they just stop

Looks like some heat stress too. What are your temps?

the temp is at 24

Don't let it go over 80 how far are your lights from the canopy?

Pic 5 looks a little like too much nutes maybe...but shifting ph does cause problems... I killed a plant doing that the last round, what is your humidity?