Need bigtime help!!!

[Hutch]

Could someone please take a look @ photos & give an opinon as to what happened? The plants are " Nirvana Misty." Grown under 400W Hortilux, first time using this light. Previous grows under 320w fluor. Used Peters 20-20-20 for veg & Green Light Super Bloom 12-55-6 for flower. Previous grows did not have this problem, they were about as good as you could get using that wattage fluor. 400w stayed about 4" to 8" above plants. You could hold hand under light & it was not hot. The only thing different this grow was light & I let plants get dry enough to wilt once.
I would really appreciate some help as I will be starting another grow of Misty soon. Thanks in advance. Hutch

 

[sproutco]

Ammonium toxicity

Ammonium toxicity

12-55-6 is pure ammonium nitrogen. It also lacks all the micros except iron and calcium, magnesium, sulfur. Too much phosphorus can be bad on plants. This fert contains quite a bit. It builds up in the soil and can cause micronutrient deficiencies among other things. Find a better bloom fert.

Peter's 20-20-20 is not really any better with almost all ammonia or urea nitrogen. It does contain all the micros but not really in a good proportion. It still lacks calcium, magnesium, and sulfur. There are better veg ferts high in nitrate nitrogen.

Rule of thumb: At least 1/2 of the nitrogen you using should be nitrate nitrogen.

 

[keeko]

looks like nutrient burn, how much did you feed her?

 

[Hutch]

I used same ferts on previous grows without problems. Never fed more than half strength every third watering. Will be using GH Flora Series with next grow. Also what is a good inexpensive ph meter?

 

[sproutco]

Flora series recipes

Flora series recipes

ml per gallon of water...

GH's baseline Flora Series, the 3 bottles, green purple and red, (different from Flora Nova series) veg formula
GH 15grow, 10micro, 5bloom
211 n
46 p
263 k
40 mg

Use 1/3 strength veg formula for seedlings and 1/2 to 2/3 strength for regular growing.

and GH 3 part bloom formula
GH 5grow, 10micro, 15bloom
159 n
92 p
219 k
66 mg

You want about 100 n in flower. You can see 159 n is a bit much. Use 2/3 strength.

Because these ferts are high in calcium and magnesium, you should use little dolomite lime in your soil mix. See how to make a soilless mix in my signature below.

Good luck on the next grow!

 

[MynameStitch]

I keep on telling people, stuff like this. Using a nutrient that is not balanced like that and when it does not have certin nutrients it requires in there this happens.

Does not matter if you used half or not, because it causes more of a balance when you use less of that.

Like sproutco has stated using something that is more balanced, but in flowering you want less nitrogen and more phoshprus and potassium. You still need some nitrogen but not high levels.

You want to keep it balanced out and make sure your plant has all the micronutrients it needs.

Calicum, magniseum sulphur ect.....

 

[Hutch]

I'm using Pro-Mix BX W/Mycorise with no additions. It has dolomite in it, do I need to add more?

 

[sproutco]

Use the promix straight from the bag. If your going to use the flora ferts, don't add additional lime.

 

[Hutch]

Thanks for the help guys. One more quick question. Ph meter, where, what brand?

 

[sproutco]

Features to look for in a ph meter:
>auto temp adjust
>waterproof
>able to be calibrated
>replaceble tip rather than the whole meter being disposable
>best feature: able to be stored dry
>warranty on the meter

I think quite a few people use Hanna. I also heard Oakton was pretty good.

Be sure to get some solution to calibrate the meter to.

 

[Hutch]

Thanks for all the help sproutco.