New Grower Which deficiency is this please?

[churchill]

Hi there

Into the third week of my first grow and need help on this please...

A few days ago one of the girls started showing brown spots on her lower fan leaves. This spread to covering the entire lower leaves brown and drooping. This has started on several of the other girls now as well. The rest of the plant looks good.

My set up is as follows:
* Temp - 26 degrees
* Lights - 2 x 900w LED's approx. 24" above
* Humididty - 35%
* 8 pot RDWC
* Res Temp - 22 degrees
* PPM - 500 (Tap water - 68 ppm)
* Lucas Formula General Hydroponics Flora Micro & Bloom @ 75% for Veg Cycle

I am on day 17 right now. After researching I thought this looked like nitrogen deficiency. I thought that the nutrient solution maybe took weak. So I added another 50ml of Flora Micro yesterday. But no change yet. Other areas it seems it could be are Cal Mag or Molybdenum deficiency.

 

[Dark Matter]

Could be several, but from this chart. Its looks to me like Phosphorus! But you can see if you have a keener eye than me and decide for yourself Bro.

 

[A4]

1st and 2nd plant look like phosphorous, 3rd looks like calcium.

Looking through your numbers I noticed you didn't post res pH. Everything else looks good, your temps on your res is a little higher than I would like which may be attributing to some fluctuations in pH swing.

 

[ripster]

Your humidity is to low, and by the looks of the plants, I'd say it appears that they are to wet. Drowning. I say that because the leaves r drooping but your running hydro, so...IDK about that. Never ran hydro before.
Try adding 1/8 tsp, per gallon of water, of Epsom Salt. Keep your PH between 6.25 and 7.0 In that range, the plants will be able to consume all the nutes. So you don't get nute lock out.
Boost your humidity and lightly foliar feed till they bounce back.
Good luck....

 

[churchill]

1st and 2nd plant look like phosphorous, 3rd looks like calcium.

Looking through your numbers I noticed you didn't post res pH. Everything else looks good, your temps on your res is a little higher than I would like which may be attributing to some fluctuations in pH swing.

Sorry, PH is 5.9

 

[A4]

Sorry, PH is 5.9

I would say your res levels are too high or you don't have enough dissolved oxygen in your water then. Where is your level set at? The higher the temps on your res the less oxygen the water is able to absorb, something to keep in mind. Ripster was correct in one aspect, your RH is pretty low for veg but that isn't what is causing your problems. I am sure you know not to follow his instructions on pH but just in case.....don't follow his instructions on pH.

I am assuming you have checked your roots and they are looking good also?

 

[Panic]

I put money on a water issue, what do the roots look like? Like I know I can't really do DWC because my water temp is too difficult to maintain consistancy; temps typically get above 80-85+F . The root zone would start to to necrotize the plant would visibly crash, so I'd H202, which worked temporarly. Water consistancy... cause you play all day trying to foliar and push nutes. PH is a low for DWC but not out of whack. I think A4 is probably right. I hope it gets better.

 

[Waira]

:smoking: Yup, I agree with A4, P defc. on first two, Ca on the 3rd,... Now, I'm not hydro-experienced, but that ppm looks low, a little thin on nute's,... Also, Ca and P are already availability-twitchy at this pH in general, so if levels are low, likely you have a plain old lack-of defc. issue, not a pH lock-out one-- easy fix! Up your nute' ppm's.... Let's see if A4 agrees,....

 

[churchill]

OK just got back from work. Firstly, A big thank you to you guys who took the time to help me out!

So I have taken action…

* Reduced water level in pots
* Raised Nutrient to 600ppm (Lucas Formula Veg 0-5-10)
* Lowered PH to 5.6
* Light Foliar spray

I've noticed it's like a jacuzzi in the pots. I didn't expect so much splashing onto the underside of the lids though. My net pots are 140mm deep. I have had the water level about an inch below this as recommended. I should have realised before that the bubbling if saturating the underside of my lids would be saturating the hydroton all the way up to and including the sponge. Hence why they look a bit overwatered I guess.

Does anyone think I should be adding Cal Mag to my feed or anything else? I have just been using GH Flora Micro and Bloom so far. I am hoping the increased micro and bloom nutrient, combined with lowering the PH, will address the phosphorous and calcium issues.

Roots seem absolutely fine to me. Good white pearlescent colour and pretty substantial for just over two weeks old I'd guess.

My DIY system if it helps is an 8 x 30 liters pot RDWC. I run a 10k L/H water pump and an 80 LPM air pump. I fill the pots with 20 litters and get a recirculation rate of about once per minute. The water to air ratio in the pots are 2:1 (20l water & 10l air).

 

[ripster]

Magnesium sulfate is commonly known as Epsom salt.
Sorry about the bad info on the ph. It slipped my mind that in hydro, your ph is lower, my bad...