Brown spots on plants at 28 days old

I am really hoping this is me over reacting, again… Or at the very least, a simple fix… I have tried to stay on top of everything since this is my first grow and I really am just learning…
So, I have a 2x4 tent with a Viparspectra 600 watt LED light at about 40 inches from the plant… I have DWC pots with 2 airstones in each pot… I use Distilled water with Flora Trio, Cal-magic, and Hydroguard at 350 - 400 ppm… The pH rises, but I am keeping it at about 5.8 (if my pH meter is correct!!). I did calibrate the meter, but I just don’t trust it… My tank water temperature is about 68 degrees and the air temperature is running 72-78… The humidity varies, but I put a humidifier to keep it between 35 and 55%…

Let me know if you need more info…

Check pH with, paper to double check, also plants are sensitive with to much calcium, check the amount, maybe lower the Cal? Hope this helps, aloha!

I put quite a bit less than the recommended dose of calmagic… but I can do less at the next water change… unless there’s a way to lower the amount now???
Also, the pH paper is not very accurate at all… Maybe I have a touch of color blindness that I didn’t know about but I have issues telling between 5.0 and 6.0

You’ve got to get yourself a Ph meter. Most problems are due to improper Ph. Papers and drops are not accurate enough for our needs. You’re not color blind, its just the Ph strips are really hard to read. Here is a good Ph meter that many of us use here:

There cheaper ones too that you can also get, but this is everyone’s favorite.

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I have 3 different ph meters… Everything from a cheap $10 meter to the $40 Dr Meter… However they all read different even after calibrating 2 to 3 times each!! I ordered more calibration packets to do it again and agai. if necessary, but how do you trust them when they are all different…

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Hmm, that is a problem. I would go with the best meter you have, its probably the one that’s accurate, but using the Ph strips isn’t going to help you. Try calibrating them again and I would not use the cheap one.

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I agree… The Dr Meter is supposed to be nice, but the calibration is VERY confusing!! And I am not a moron, but it is not clear at all… I am a Civil Engineer so it is a touch embarrassing, but I work at a University with a Chemistry Department… I believe I will have the department head calibrate it for me… She is very nice and fun to talk with anyway :smiley:


Lol, I know how you feel! I’m an architect, but some of these things make me feel like a complete idiot, so you’re not alone, my friend. :relaxed:

Hello there, ya by all means have her do that for ya and You`'ll be all setup both ways…lol

So, I am definitely stumped on what to do now with these plants… The new growth appears ok, but the old is getting much worse… I am trying not to make massive changes since I could be overreacting but at this point, I am afraid I am just not making the correct changes… My ph meter is 100% correct… I am using distilled water in 3.5 gallon Bubbleponics buckets that takes about 2 gallons to get the water level correct… My nutrients (flora trio) are running between 500-600, which includes 3ml micro, 3ml grow, 3ml bloom, 7ml cal magic, and 2ml Hydroguard… The old fan leaves that originally had brown spots are now dry and shriveled… The air temp is staying at 75 degrees, the reservoir water temp is staying about 68 degrees and the humidity is at 40 to 50%… The roots are getting plenty of bubbles and are not slimy at all… Should I flush everything really good and start with a fresh water in each reservoir??? I don’t want to overreact if I fixed the issue, but I also don’t want to let things get worse…

@Donaldj is a good ol dwc guy that can probably answer your questions

Actually in discrete mode atm have 17yr old daughter over for the night so trying to avoid pictures on my monitor :wink: which are half my thinking process unless we have a support ticket with no pic?


@Donaldj I could use some advice when you have some free time and are not in discrete mode… I feel like I have done everything correct… Or, at least I have tried to… I am now afraid my initial issue was no big deal, but I made worse by overreacting and overcorrecting… I can give you my email or my phone number if that is easier for you…

No and No both are against forum policy
what you can do is post details of ph res temps, climate strain age of plants. Nutrients currently in use (how much and what) additives and anything you can think of aside from a picture. My problem is 6’ distance between me and a kid that would recognize pictures :wink: if that makes sense I do have the time just not the privacy

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7ml Calmag is pretty strong dosing and the fact none of the top growth is affected is a good sign could mean a mistake made early which you unknowingly fixed I assume all measurements are per Gallon not total volume of res?


Ok, I will start from the top…


This is my first official grow on my own… I am growing GG#4 from Doc’s Dank Seeds… I germinated the seeds using the paper towel method and put into rockwool as soon as the tap root appeared… I kept the rockwool in the humidity dome for the next 1.5 weeks and noticed they seemed to be growing very slow… I was informed that I was likely overwatering… I cut water back and when the 3rd set of leaves appeared, I put the rockwool in a 6" net pot that is in a 3.5 gallon Bubbleponics bucket and added the first nutrients (flora trio at 250 pp.) **At this point I did not add Hydroguard nor calmagic… The roots were not touching the water at all so I did a combination of top watering and keeping the water level in the reservoir a bit higher… Once the roots started to touch water, I lowered the level and stopped top watering… I try to keep the level at approximately 1 inch below the bottom of the net pot…


I started with The flora trio micro, grow, and bloom in distilled water amounts that gave me 250ppm… I used the ratio 2:1:1 → micro:grow:bloom… This was the ratio for the first 2 weeks… I got the basic dose from the chart below… I did adjust it as I noticed whether the nutrients seemed to be going up as the water level went down… When I first put the nutrients in exactly how the chart said, my PPMs were 800+… I was told that was way too high so I diluted the mixture to get it to 250… Since then, I have added C almagic and hydroguard… I changed the tank 4 days ago (it is only 2 gallons to have the water level correct) and that’s when I put 3ml of micro, 3ml of grow, 3ml of bloom, 7ml C almagic, and 2ml of hydroguard… That is the total amount for the 2 gallons reservoir… It made the PPMs about 550 to 600…

Temperatures and ph

I had temperature and humidity issues in the beginning!! The reservoir water temperature was over 80 degrees for about a week, The air temp was at or close to 85 off and on during the same time period… And the humidity was in the 20s… By week 3 I got these things under control… I added a extra fan to circulate air better… I left a top section of the tent unzipped so heat has an easier way to escape… The air temp stays between 70 and 78, but rarely goes above 80… I added a humidifier so now the humidity is staying about 40 to 50%… And I am watching the reservoir water and have kept it in the high 60s (68 most of the time)… I consistently checked my pH and tried to keep it at 5.8, but I was using a cheap meter… I bought a much better meter and got it calibrated so, I believe it is much better… Note: Over the past 2 days, the reservoir water has been consistent and I have not needed to adjust ph at all…


I initially noticed slow growth… I attributed that to overwatering and let things dry out… Then once the roots hit the water of the reservoir, the growth took off!!
I noticed some of the early leaves were canoeing a tiny bit, and asked, but most seemed to think it was very minor… I raised the light from 36 to 44 inches from plant…
I noticed the brown spont and was told calcium deficiency… I added the Calmagic and hydroguard…
Now, the leaves that were brown spots and had a minor canoeing are all but dead!!

The tent is a 2x4 grow tent…
I am running DWC Bubbleponics buckets with 2 airstones in each.
The Light is a viparspectra 600 watt at 42 inches from the top of plant…

I am sure I am forgetting something!! Let me know if you need more info!!

be less stringent with this to start ph 5.5-6.2 is fine set close to 5.8 at changes and adjust again after 24hrs as nutrients interact and set all top offs lower or higher depending how res ph is 5.6 higher 6.1 lower etc. Some ph swing is fine and actually will help plant get broader nutrients into perfect range :wink:

They had heat stress and true extent of damage takes days to see after any issue focus on new growth as a rule the older leaves tell you what happened last week the newer ones yesterday. Heat stress drys stomata shut so plant stops directing energy and water/nutrients to them at that point takes several days for them to dry out meantime plant will leach some nutrients out of them. Lower leaves are prediction of what could be happening but in some instances we move on knowing they had a rough go at a certain known point to blame the damage on.

This is a good sign it means you have found a sweet spot in ratios and ppm but will last briefly since naturally your plant will need more as it gets larger as you noticed they grow ever faster all the time I hate small res buckets because soon plants will be drinking over or near to 1/4-1/2 that res in a single day. Even 5 gal rarely works perfect I favor using totes with painted lids and netpot. The greater the volume of res the more stable it is temps ph and ppm

Things of note:
everytime you adjust ph ppm changes this change is an acid or a base not usable to plants. Ph is a range not a point :wink:
old damage only goes away with scissors once a leaf is starting to brown almost never can be fixed, discolorations yellowing can be
A larger res is your friend if your plants are drinking without eating ppm raises super fast in smaller res leading to nutrient burns huge ph swings and temp climbs

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Do you believe it is ok to remove damaged leaves?? Do you think it is now under control?? I ordered a 27 gallon tote and am going to switch to a RDWC… This way I can use 4 - 5 gallon buckets and keep the 27 gallon tote outside the tent… I was going to wait until my next grow, but I believe it may be b enificial (if I can get the new RDWC set up and running correctly) to go ahead and strict these plants into the RDWC system… I am going to put the entire thing together first and let it run with nutrients for a couple days to see if everything is running correctly before I put the net pots with plants into the system…

removing damaged leaves is ok if they no longer look to be helping plant any. Upgrading your system can be done at anytime

I removed the obviously dead leaves… There’s a couple more that have some damage, but it is unsure if they will dry up completly… It totally makes sense that there was heat damage since my heat was way too high in a couple different ways right about the time that those leaves would have been forming…
I did remove a few cups of water from the buckets and replaced with plain distilled water to lower the PPMs to about 350… The pH is staying consistent, especially since I had a chemistry professor at the university where I work to calibrate my pH meter and show me how :grin:… Thank you for all your help!! I will continue to post ongoing pics and will post a formal Grow journal with pics once I get further along… I have been keeping pretty good records…
Pics from today

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