Yellowing and some dropy top leafs.I need your advice:)

It is my first grow.These two babes are 23 days into flowering.I dont know what kind of strain.I cant give you any info about nutes because i was experimenting and i cant remember.I saved them from nute burn 30 days ago.Know they look ok beside the yellowing and that some top leaf looks like the N toxicity symptom.Can any one tell me what is causing yellowing?I didnt add any nutes the last 15 days because i had problems with N toxicity.

My big worry is that i didnt use perlite with soil.Now i see that soil is very hard as rock and i cant see roots on the top of the soil.Is it possible to get root rot because of that?

Take a look a the first pic at the right corner of the photo.

if you lay a tarp or a garbage bag on the floor and lay the plant on its side so your buds dont get dirty. then try to get the pot loose without damaging the plant and take a peek at the roots if they look brown then your getting root rot.you might not have enough air to the roots. next time add that perlite. I would keep feeding it. looks a bit hungry

Too yellow too early because your using the wrong medium and the wrong nutes. They wreck the ph and deposit salts in the soil in turn this stops N uptake. Also the salt build up is worse when you let the pot dry too much then only water a small amount in. To reduce salt build up always water until plenty of run off, use good coco or hydro medium and hydro nutes..

thanks guys.PH is 6.5 to 7.I was feeding with 20/20/20 at veg stage.I was trying to keep it at half dose of the instructions on the side.But i got N toxicity and flashed them and gave them nutes after two weeks.Since then everything was fine.Old leafs didn't recover but both plants were happy.
I checked the root system everything is ok but medium is rock solid.I think roots don't get enough air, or water cant penetrate inside the root ball.I noticed that water was running off so soon so I always water them slowly so that the medium has the chance to absorb water.I always let water run off. Thats what i do for years with my other plants at the balcony in the front of my house.I always let a run off or else salts can build up very quickly.

A friend gave me a guanokalong - taste improver.Is it ok to use it for flowering stage?
the instructions say Flowering: 10-30 ml per lt. once a week

lets hope they will grow until the end. new pic added

That's not a bad first grow im proud of you. 20 20 20 is fine for vedg. have you tried any calmag? calmag will help green things up a bit use at half strength.I have no idea about guanokalong.

Thank you Dr.Pecker.Im using 6x32 cfls. Im well experienced with other plants but never had an exp with ganja.No i haven't tried.Is it expensive?can you give me a link of that product to check a similar product in my country. Check the pic. this is my biggest worry.It looks like over watering.Im sure its not over watering.The rest of the plant is not like this.

that light is real close you might want to move it away for bit and check and see how hot that is.

http://www.amazon.com/s/?ie=UTF8&keywords=cal-mag+plus&tag=googhydr-20&index=aps&hvadid=32834964629&hvpos=1t3&hvexid=&hvnetw=g&hvrand=15937013408688627442&hvpone=&hvptwo=&hvqmt=b&hvdev=c&ref=pd_sl_81zvp5g8hl_b

this one drops your ph a little

only use them at half strength.

My highest temp at the top of the grow box ever was 28C.Temps never been more than 28.Usually are something like 25-28 C.The plant is 2-3 cm away from light.I cant feel heat if i put my hand between them.

i will remove it a little bit more to see.

thank you for your help!

cupping and curled leafs could be from heat. Just give it a couple days cfls can get hot.