Lower leaves have spots what am I missing

Hi all! First ever indoor grow and I am having some problem with 2 girls out of 3.
I have a top-feed DWC Setup with a 40l reservoir. The strain is Glookies by Barney Farm.

I have just completed week 1 of veg and the last 2-3 days I started to get spot on the lower leaves. I did a water change 2 days ago and the problem is looking to be even worse. My nutes contentration was also a bit lower for the first week of veg.

I am using the Canna Aqua lines of nutes, and right now I have;
1.8ml / L of Aqua Vega (A & B)
2ml / L Rhyzotonic
2.5ml / L Cannazym
1ml / L Cal-Mag
This is the “low feeding chart” from Canna, and half the recommended dose for Cal-Mag.

The tank is average 6.0 of PH and I have 1.3 of EC (it was 1.00 before I added the Cal-Mag). Day temp is 75-78, night temp 68-72 and humidity is constant at 50%. Exhaust fan always on, air pump and top-feed also. When lights on rez is at 79*.

Judging from the chart online I determined I either have a P lack, Calcium or magnesium defiencies, or wind burn. I moved the fan away and added half concentration of Cal-Mag. 24hr Later it’s looking to be even worse.

I guess I should add that until yesterday I had to adjust PH down from 3 to 5 times a day, it was going up about .1 per hour for the first week. Yesterday I added Cal-Mag to the mix and have only saw a small increase of .06 in PH over the whole night. Root also reached the tank about a day ago.

Any help or pointer would really help me!
Thanks a lot guys, and happy growing!

Not a hydro grower (yet) but believe this is too high. Believe water temps should be closer to 68*. I’ll call in some hydro guys. @TDubWilly @Grandaddy013 @peachfuzz


79F is not good at all. You need to be ideally at 65F. I don’t think using anything like Hydroguard would make a difference at that temp. Invest in a chiller.


Are you running air stones and how much air? Rez too?
How far below net basket is rez? It should be 2" or so below.
Why are you still top-feeding? Have the roots not reached the rez? Once they do, discontinue top feeding.
PH is a bit high and I’d prefer to see it at 5.7 or so.
When did you last calibrate your PH meter?

I don’t use that nutrient line but do know that some products are optimized for different types of water i.e. GH is meant to be used with R/O and FF in 200 ppm tap water. Mixing different lines can cause trouble (as I found out using FF cal mag instead of GH). You want something buffered for your PH range to be truly useful for RDWC.


Thanks for taking the time to help me, i really appreciate.

I am one lucky guy as I have both a refrigered and a fan type chiller here that came with my Laser. Getting the temps under room temps will much likely required the refrigered one.

I am using 2 air stone hooked up to a 40l/min pump, lot’s of bubling in the rez.
Right now water is 1" below net basket, root (well 2 or 3 small root) are touching the water since about 24hr. I will turn off the top feeding for an hour and see how they react, and won’t turn it back on if root provide sufficient water to the plant.

I’ve been suggested that my nutes ratio might be a bit too high even though I am on the low side of the feeding chart, does my concentration seems too high? I will lower the contentration before lowering my Ph if I need to. PH gauge was calibrated 2 days ago on Sunday.

The canna aqua line is made for raw tap water so I am using tap water for my mix. I also have a RO system but only using it for my humidifier.

The problem is going to be the top feed…
Are those plants in a rockwhool cube or plug of some sort…?
If there is some sort of a plug which I believe there is by the looks of your plants (ie) overwatered look… your going to create an anaerobic environment at the trunk (ie) plug or rockwhool area that is going to cause a ph lockout in your plants (ie) what your leaves are telling us…
Once roots hit the water , ditch the top feed…
I believe your high water temps and the top feed are leading to a trunk/roots before water line problem , that is leading to a ph lockout issue…
You might also need more air in your resivor’s… :+1::wink:



I turned off the top feed today. You are right i have a small rockwool cube underneath the clay pebble.
I also removed half of the water for fresh water and cut the EC in half. Currently working on getting my PH where I want it to be, then I will plumb and hook up my chiller. I can also run my air pump @ 220v for a 80l/min flow, although it’s loud af so I only run it at 110V. I could also add my small aquarium pump for a twin pump setup.

Should I cut the end of the leaves that are turning brown and drying out?

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Don’t remove anything yet. You might also put a clear dome over the plants as they like high RH right now.

For comparison I’m running a simple bucket hydro and my pump runs at 80 l/minute.


Good, I’ll bump up my air pump voltage and see if that help. Almost done installing the chiller, and I can easily dial in 60% of RH in my tent. I have a RH controller cycling on and off.

Thanks everyone that helped me today. I have the chiller fully installed now keeping my water temp at 19*. I also went ahead and diluted my rez water to .59 EC and PH’ed down to 5.75
Top feed is also uninstalled! It’s their night cycle atm but I will report back on how they perform. I Also upped RH to 58% although in the picture it’s sitting at 53% because I had just closed the tent.

I sure learned a lot everyday since I got into this :slight_smile:


24hr since I reduced my rez nutes by half and installed the chiller, and keeping a steady ph of 5.7.
The damaged leaves have started to be really pointing down but the plant in overall are still growing. They now have several roots in the water since I turbed off the top feed.
Here’s some picture of a few minutes ago;


Hoping I’m heading in the right direction, will report back in another 24hr but in the meantime I’d be happy to hear other people opinion.

Thanks to all!


Plants look like they are doing fine. Hydroton looks nice and dry.

FYI damaged leaves will not recover: look to new growth for improvement.

In a couple of weeks you bump the TDS up to 1.6 ec or so (600 to 800 ppm/500 scale)


Ramping it up slowly or I should wait for the plants to be 3-4 weeks into veg for going up higher? I plan on topping them 2-3 times and switch to flo around 5 or 6 weeks, these glookies are reputed to grow really big. Because of the way I made my rez, I cannot really put a scrog net at least that was my conclusion after my first water change.

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I’m doing a bucket hydro grow in an 18 gallon tote and faced the same problem as I’m in a little 2 X 4 X 5 tent so my vertical height is restricted. I had to get a SCROG in the space and was able to.

If you are interested; here’s my current journal. You should probably scroll to the end and then back up.

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@Myfriendis410 has you covered. Nice set up and good luck! :v::bear:


So 48hr after you guys saved me, things are looking really good! My PH Never been as stable, and the EC went down from .6 to .52 and I they drank about 5l of water. They are indeed looking much better and judging from the drop in EC they could use a bit more nutes. Since I have one that is really smaller than the other I think it would be wise to let him catch a bit before I up the EC though. The smaller one also have the smallest root system.

@ other hydro grower, are you cleaning the whole rez from all sediment and precipited stuff at the bottom of the tank or just pumping out the old water and replacing with new water? If I could get away with just replacing the water I could scrog them.

I drain ass possible water and clean really good between grows. Not sure if that’s the idea way but I scrog too :+1: