brown spots, some twisted leaves and some tips curled down

I'm honestly completely stuck at what the problem could be with my plant. It's been flowering for maybe a month or more. It started getting brown spots all over the leaves (but only some leaves). They're little speckles and over the whole leaf, not just the tips. They're not yellowing either, only a couple of the leaves have actually died and those leaves turn completely brown/black and yellow from the tip. Also, some of the tips of the leaves curl down but then other leaves are twisted. None of the leaves have ALL of these problems. All of these problems are not concentrated in any particular area of the plant either. I'm currently using Iguana Juice Bloom which is 4-3-6. I know it's not over-watering and all my research on deficiencies has turned up no like situations. The curling of the leaves may be that they are getting too cold and I'm not as worried about that as I am the brown specks. It doesn't seem to be affecting the growth of the actual plant but I am worried it could affect the growth of the buds. It got down to 64 a couple days, could that be locking certain nutrients out and causing these problems? Could it be some type of bug? I haven't seen any flying bugs but maybe something in the water or soil? I was using water from a reservoir but stopped after seeing the spots thinking it could be something in the water. I will upload pics when the lights come on. help meeee :)

It sounds like you have a few problems here, not just one thing... the first thing that comes to mind is the pH level of the water you're using. That will determine what nutrients are being locked out... use the below chart (if it displays properly..lol)

Attachment 281235

oh yea i forgot to put that the pH is 6.4 so i don't think that's the problem :(

If you give better info concerning your grow you might get more accurate answers. If i were you id start with the trouble shooting form. Fill that out as complete as you can, paste it on here and im sure someone on here will be able to help you out. Good luck

it's possible it could be calcium deficiency, if so how would I fix that?

I use RO water with my plants and have to use 'Cal-mag' to make up for the calcium removed from my water... Cal-Mag is sold by 'Botanicare', but there are other hydro suppliers that have the exact same thing under different names..

alright i will try that and also try to keep the temp a little more even.

Attachment 281251Attachment 281252Attachment 281253

From what i can tell, it looks like a potassium deficiency. Of course that's without seeing the rest of your plant.
If your lights are HID's the plants under those lights can use more food than plants under floros.
4-3-6 seems really week. But your plants could be smaller than they look or sativa dominant...so there's that.
to get a better diagnosis, please fill out one of the forms that are stickied in this forum. light wattage, plants size, sativa or indica dominant?
these questions and many more are the key to getting a lock on the problem. you have growers on here with years of experience that know
how different variables effect plants. More info is always better when it comes to diagnosing issues, even if you dont think it matters.

Hope this helps...

Now I'm going out on a very long effing whim here....but IMO....it appears as though your plant has a problem in the root zone.... And the problem might be that the amount of soil being used is too great for the size of plant.... If so, and if you over watered, your roots at the bottom of the pot are staying wet and your soil doesn't dry out evenly....thus giving you the appearance of a problem.... It also appears as though your lighting is insufficient....

But like I first said....that's just a guess.... The troubleshooting form is in my sig....

CGI::::::

What is your experience level? (first timer, novice, experienced...) Novice - 5 grows

(I only have one plant flowering as of right now)
Your Equipment:
.1) Type and wattage of lights. (MH, HPS, CFL's, tube fluorescents, LED's) - 150w HPS & 2 68w CFL's 2700k
.2) Distance from top? 5inches
.3) Reflector type? (cool tube set-up, bat wing, enclosed reflector, bare bulb...)bat wing
.4) Is there a consistent fresh air supply? yes
.5) Do you have an exhaust fan and a circulation fan? yes
.6) What are the bulb wattages, kelvin ratings, and schedule? (above) schedule is 12/12

Your medium:
.7) Specific brand and type of soil, (coco, peat based soilless...) and anything you've added to it. (vermiculite, perlite, worm castings...) Indoor grow mix mostly coco fiber
.8) Size of container - 10 gallon
.9) Did you use peat pucks (or similar) to root clones or germinate seedlings? no

Your nutrients and water:
10) Source of water? (tap, bottled or filtered) What's it's ph before adjusting? tap, unknown water pH but soil pH is 6.4
11) Method of checking water ph. (ph pen, test strips, aquarium test kit...) n/a
12) Method of adjusting water ph. (phosphoric acid, white vinegar, hydrated lime, PH Up...)n/a
13) Specific brand and N-P-K ratio for each bottle. List dosages (quantity per gallon) and current feeding schedule. Iguana Juice Bloom 4-3-6 & Voodoo Juice
14) How often are you watering between feedings, and how much per watering? once - gallon
15) Any additives or tea's? (Superthrive, CalMag, molasses, Mother's Earth...) no
16) Are your ph levels stable, or do they fluctuate? stable soil pH
17) What is your ingoing water's ph? ...your runoff ph? unknown
18) Do you foliar feed? If so, with what, how often, and at what time do you spray? no

Your growroom:
19) Indoors or outdoors? indoors
20) What size of closet, room or hut? 2 x 5
21) What are the temps and humidity levels while lights are on? ...With lights off? On - 78 degrees w/ 35% humidity Off - 68 degrees w/ 30% humidity (since yesterday. i have been keeping the temperature up when the lights are off but previously this were the readings ^)
22) Have you seen signs of insects in the growroom? no but have lady bugs

Your strain:
23) What strain are you growing? (Indica dominate or Sativa dom?) sativa dominant
24) From seeds or clones? seeds
25) Is this an autoflower strain? no

well i hope this helps with determining the problem

the nutrient feeding is 16 mL per gallon and feeding once a week.

any ideas :/