Led grow yellowing and burn help please

[Plarntmarn16]

This is my first grow.
Details as follows,

Tent-60cm x 120 x 150
Flood and drain buckets- 20L flooded for 4 minutes 4 times a day
Medium- clay balls
Strain- ak48 x 2 in tent week 5 in veg both 20cm high
Light- Mars hydro led 450 w 144x3 5 w 60 cm above plants. 18hrs on 6 off
Air flow- 1 hydroponics fan in tent 1 exhaust fan sucking air out.
Ph- 5.7-6.4, 80 percent of the time at 5.8-6.1
Temp- kept between 18c-26c
Res- 45L ec of between 1800 and 2000
Nutes- general hydro flora nova grow and calimag, mixed 1 ml per for Calimag and the rest made up of flora nova grow to reach desired ec of 1800-2000.

My problem is from week two I have had problems with tip burn and yellowing of leaves. Nothing I have done seems to stop the problem. It does t get any worse or better and the plants keep growing. At first I thought it was over watering so I dropped from 5 times a day for 15 mins down to 4 times to 3 times then to 4 times at 4 mins now I'm at 3 times at 4 mins. No change. Then I thought it was the LED was too close so I raised them from 18inch to 25 inch. No change. I change the nutes every two weeks and flush clay balls 2 or 3 times during that period to prevent build up. I read that LED need calimag so that why I have used that from the start. Can anyone pleaaaase help???
Thank you.

 

[rkymtnman]

did you say your EC is 1.8 to 2.0? if so, i think that is way too strong. i never run over 1.2 EC even when they are flowering like mad.
i'd give them a flush for 24hrs with just pH water 5.8. then start back on the nutes way lighter. still use cal/mg though as you were doing.
i've never done flood and drain so not sure if you are doing it too much, too little or just right?

 

[bf80255]

This is my first grow.
Details as follows,

Tent-60cm x 120 x 150
Flood and drain buckets- 20L flooded for 4 minutes 4 times a day
Medium- clay balls
Strain- ak48 x 2 in tent week 5 in veg both 20cm high
Light- Mars hydro led 450 w 144x3 5 w 60 cm above plants. 18hrs on 6 off
Air flow- 1 hydroponics fan in tent 1 exhaust fan sucking air out.
Ph- 5.7-6.4, 80 percent of the time at 5.8-6.1
Temp- kept between 18c-26c
Res- 45L ec of between 1800 and 2000
Nutes- general hydro flora nova grow and calimag, mixed 1 ml per for Calimag and the rest made up of flora nova grow to reach desired ec of 1800-2000.

My problem is from week two I have had problems with tip burn and yellowing of leaves. Nothing I have done seems to stop the problem. It does t get any worse or better and the plants keep growing. At first I thought it was over watering so I dropped from 5 times a day for 15 mins down to 4 times to 3 times then to 4 times at 4 mins now I'm at 3 times at 4 mins. No change. Then I thought it was the LED was too close so I raised them from 18inch to 25 inch. No change. I change the nutes every two weeks and flush clay balls 2 or 3 times during that period to prevent build up. I read that LED need calimag so that why I have used that from the start. Can anyone pleaaaase help???
Thank you.

try dialing back the nute strength to 1/3 or 1/2

 

[Plarntmarn16]

try dialing back the nute strength to 1/3 or 1/2

thanks for you're reply.
Ok I'll try that. Do you have any idea what the maximum ec should be on such a set up?

 

[Plarntmarn16]

did you say your EC is 1.8 to 2.0? if so, i think that is way too strong. i never run over 1.2 EC even when they are flowering like mad.
i'd give them a flush for 24hrs with just pH water 5.8. then start back on the nutes way lighter. still use cal/mg though as you were doing.
i've never done flood and drain so not sure if you are doing it too much, too little or just right?

Thanks for your reply mate oh really? Well I'm a little confused as to what ec I should use, I've been told to use an ec of 18-20 during late veg. Also my ec meter measures ec as a larger number like 1800-2000 is that normal?
Has anyone else got any experience on flood and drain ec or ppm? Thanks in advance

 

[rkymtnman]

1800 is the same as 1.8 EC.

i'd flush for 24hrs for sure. the tips are burnt from too strong nutes. try 5mL per gallon water of the FN grow and see how the new growth looks.
what water are you using?

 

[Plarntmarn16]

1800 is the same as 1.8 EC.

i'd flush for 24hrs for sure. the tips are burnt from too strong nutes. try 5mL per gallon water of the FN grow and see how the new growth looks.
what water are you using?

Ok so you flush with ph 5.8 water for 24 hours and then add a new res of what ec nutes would you recommend?
My water is tap water with an ec of 230

 

[bf80255]

thanks for you're reply.
Ok I'll try that. Do you have any idea what the maximum ec should be on such a set up?

18 hours ON with a 450w LED
in hydroton, flood and drain
in veg... id say around 700ppm-1000ppm (higher end is for nute whores) [800 would probably work]
EC .75-1.5 [but id stay around 1]

 

[bf80255]

Ok so you flush with ph 5.8 water for 24 hours and then add a new res of what ec nutes would you recommend?
My water is tap water with an ec of 230

get yourself an RO filter itll help dial your grow in much better.

1800 is the same as 1.8 EC.

i'd flush for 24hrs for sure. the tips are burnt from too strong nutes. try 5mL per gallon water of the FN grow and see how the new growth looks.
what water are you using?

I would recommend a light solution like 1/3 strength instead of just plain water, going from a super high ppm to nothing can shock your girls.

 

[Plarntmarn16]

18 hours ON with a 450w LED
in hydroton, flood and drain
in veg... id say around 700ppm-1000ppm (higher end is for nute whores) [800 would probably work]
EC .75-1.5 [but id stay around 1]

Haha true. What would you recommend for flower?

 

[rkymtnman]

i wouldn't go higher than 1000. your water is already 230. so you only need 800 more from nutes and calmg.

 

[bf80255]

Haha true. What would you recommend for flower?

really depends on the strain and even more specifically the pheno your running but like @rkymtnman said 1.2 is probably as high as youll need to go unless your running a really heavy feeder like AK47 or something

 

[rkymtnman]

like i said, you shouldn't need more than 1.2 in flower either.

get yourself an RO filter itll help dial your grow in much better.




I would recommend a light solution like 1/3 strength instead of just plain water, going from a super high ppm to nothing can shock your girls.

i think the strong nutes has locked his plants up causing the other issues other than tip burn. i've never had a problem with a 24hr flush of plain water.

 

[Plarntmarn16]

get yourself an RO filter itll help dial your grow in much better.




I would recommend a light solution like 1/3 strength instead of just plain water, going from a super high ppm to nothing can shock your girls.

Oh ok true thanks!!
The bottle said to put in way more than that. I guess that's how they sell lots of nutes

 

[bf80255]

like i said, you shouldn't need more than 1.2 in flower either.


i think the strong nutes has locked his plants up causing the other issues other than tip burn. i've never had a problem with a 24hr flush of plain water.

if it works for you, then it probably works
million ways to skin a cat I just wanted to enter my 2 cents lol

yea these girls are gunna need some lovin! good that youve assessed the problem and are taking steps to fix it, keep us informed of there progress please.

 

[Plarntmarn16]

if it works for you, then it probably works
million ways to skin a cat I just wanted to enter my 2 cents lol

yea these girls are gunna need some lovin! good that youve assessed the problem and are taking steps to fix it, keep us informed of there progress please.

Cheers mate. Will do. Nute ec is really the only Haven't researched heaps because I thought I could trust the bottle and the sheet the hydro guy gave me. His sheet said 2200-2400 ec in flower

 

[rkymtnman]

if it works for you, then it probably works
million ways to skin a cat I just wanted to enter my 2 cents lol

yea these girls are gunna need some lovin! good that youve assessed the problem and are taking steps to fix it, keep us informed of there progress please.

the only times i flushed with a weak nute solution was growing in coco. but either way weak or plain water would do wonders for getting rid of excess nutes.

 

[rkymtnman]

Cheers mate. Will do. Nute ec is really the only Haven't researched heaps because I thought I could trust the bottle and the sheet the hydro guy gave me. His sheet said 2200-2400 ec in flower

are you going to use nova bloom for flowering?

 

[Plarntmarn16]

are you going to use nova bloom for flowering?

Yeah nova bloom for flowering. They are ak48 fems

 

[rkymtnman]

Yeah nova bloom for flowering. They are ak48 fems

good. here is my suggestion for ya. http://lucasformula.com/

check out floranova section. 8mL per gallon. BUT you HAVE to use 0 EC water. it would be worth it. you won't need calmg either. use it for all of flowering.

i buy 5 gallon jugs of RO water at Walmart for 37cents per gallon. i use 10 gallons a week. so pretty cheap and you know exactly what is in your water: NOTHING!