Tangilope trouble

[Burnit]

Hi all,

First time post been a lurker for a few years on and off. I have some trouble with my girls indoor under t5 4ft high output been vegging clones for 2 months. Just flipped the light cycle today. The tips of the leaves are burnt and curling upward also the color of the leaves are yellow. Looked at a few pics on the web from what I can tell it may be too much or too little K. Or maybe magnesium? Two clones of Tangilope sativa dom, growing in 3.5 gallon airpots. This is a soil grow using roots 707, I have supplemented it with home made worm castings, alfalfa, kelp meal and a bit of azomite over the last two months. Space is a 4x4 tent 6 inch exhaust blower at the top two small clip on fans blowing on the tops of plants. Heated with a oil filled radiator heater on a thermostat.
Temps not below 70 at night and in the high 70s during day measured at the canopy level. Humidity right around 40 percent mostly. Water most every day with a bit more than a quart per plant. Cheap moisture light and ph meter reads about 7. I have been spraying with a silicon (K) and kelp spray. As for nutes no schedule make tea from castings, alfalfa meal a bit of molasses or Neptune's harvest fish fert. Water with that maybe once a week or so.

I tried to link pics below Thanks for looking.

 

[Dan Ultra]

Fill out as much of this as possible

How many plants? What Kind?
How old are they?
Indoor or outdoor?
How big is your area if its indoors and is it well ventilated?
What medium/soil are you using?
Whats the size of the containers?
What's your lighting set up?
What's the temperature and humidity like at any given time?
What's your pH like, both medium and nutes?
What's the NPK of all your nutes?
How often are you feeding with nutes?
Any pests around?
What is your watering schedule ...

 

[Burnit]

Thanks I added some more information.

 

[Dan Ultra]

A pH of "about 7" is not exact enough and too high if it is at 7. In soil you want a pH of 6.5 ideally. Much higher or lower than that and you are going to lock out certain nutrients. Take a look here

 

[Burnit]

Thanks for the info. I realize that pH can be a problem and that ideally it should be 6.5. I have a soil test kit and pH test strips for pool testing. That is the extent of my test equipment. I grow very little so purchasing a pH meter or a tds meter for an exact measurement is not something I can justify. I have only used organic ingredients on this grow my understanding is that the organisms in the soil will keep the pH in check?

 

[Dan Ultra]

Mmm.. No that's not true. There are certain soils that "buffer" the pH, but I've read issues on those as well. You can get a decent pH pen and solution for under $25 and it could potentially make or break your grow. Without knowing what your pH is exactly, it's hard to make a diagnoses. You might be giving it plenty of what it needs, but the plant can't absorb it because it's in the wrong pH range.

 

[Burnit]

Oh I had thought that was one of the benefits of growing organically. I am pretty sure that the water here is at 7 at least that is what the test strips show. I may add a bit of vinegar or lemon juice and see how that goes. Would you be able to link to the meter you mentioned for $25? Thanks again.