RDWC rookie w deficiency problems…PLEASE HELP!

Hello all, been following for a long time but this is my first post…

Was a soil grower for many years, took several years off (my how things have changed!) and now I’m back but giving RDWC (Current Culture) a try because I’ve heard/seen great things and just don’t want to deal w the hassles that come w indoor soil grows.

I’m using the 8 bucket (13 gal) XL system with two California Lightworks Solar system 1100s. In addition to that, I have 6 plants in soil sharing the same lights.

the seeds in the RDWC were purchased through ILGM and the soil seeds came from a bag of some super funky Guerilla Glue (have yet to determine gender on these) that I wanted to give a shot.

Soil- 2 to 1 mixture of Mother Earth Coco and Happy Frog soil. Back in the day I always used Premier Pro Mix so this is first time using both of these. Water is tap water and comes in at about 300-330 PPMs before adding nutrients. I always let the tapwater sit for two or three days before using it to ensure that chlorine levels drop before watering. After nutrients are added I adjust PH to 6.5.

RDWC- using RO water that comes in at roughly 25 PPMs before adding nutrients

  • this is actually my 2nd attempt w RDWC. 1st attempt i experienced similar issues to what I’m going to explain here but it got so bad that I decided to scrap them all and start fresh…only to run into the same problems again. So, I’ll simply explain what I did this round to get where I’m at.

NUTRIENTS- Botanicare Products

Soil problems- not sure if this is where I went wrong but I did not realize that the happy frog already had some nutrients in it and I think I may not have pulled back enough when adding nutrients the first couple waterings which may have resulted in a lockout. It can be challenging to identify exactly what the deficiency is but my thoughts were iron deficiency. You guys can let me know your thoughts after looking at the pictures. The plants look really healthy for the first two weeks then I started to notice yellowing of the leaves, some became almost white. Once I started to see problems I flushed them with nothing but water and Cal Mag (3ml per gallon). Did this twice. Last watering went back and added the base grow nutrient. A few seem to be holding on but you’ll notice the others are struggling to survive. I think the damage at this point is irreversible.

RDWC Problems:
Prior to putting seedlings into the system I added Cal Mag to the RO water until the PPM’s got to about 250. I then added added Clonext solution. PPMS were around 350 and PH was at 5.7. I let this water circulate for a day before dropping the seedlings in.

On the fifth day I then added pure blend pro grow to the water bringing the PPMs to around 550. At this point the plants looked great and no signs of any issues.

At the end of week one I then added liquid karma bringing the PPMs up to 650. Towards the end of week two is when I started to notice issues of discoloring but only in two of them. I only started to notice some change in color, no rusty spots just yet. So I thought maybe they needed some more of the Pure Blend Pro. I added some of that and PPMs went to 850. Then a day later I started to see rusty spots. Having research the shit out of all of this, I assumed it to be a CAL mag deficiency so I added a little bit more of that just two nights ago bringing ppm‘s now to just over 1000…which brings us to current.

Really struggling with this as I’m down here checking 13 times a day. All my numbers seem to be what everyone says they should be. PH has been at 5.8. Room temps are mid 70s during the day, mid to high 60s at night. Humidity is usually between 55-66%. Water temps stay between 68-70F.

Lastly, are the roots. I don’t believe it’s root rot because they don’t smell and they’re not slimy. I assume that they are just stained from the nutrients but I

look to this groups guidance on that as well.

Sorry for the long post but wanted to make sure I include all pertinent information and hopes that I could get some really great feedback on this. I take pride in my work and my results. Always got great results when I did soil years ago but this is all new to me so I’m still learning. Thank you in advance for all of your help. Happy growing!


Welcome to the forum.

This is an iron deficiency. Are you also feeding a product that contains micronutrients (copper, iron, boron,…)?

This is the soil I used. so far, the only nutrients they’ve received is Pure Blend Pro Grow (3-2-4), Liquid Karma and Cal Mag.

What typically causes an Iron deficiency? Over feeding? Under feeding?

What are your thoughts on the smaller ones in the RDWC system?

We don’t see iron deficiencies very often, but it does happen. I’m surprised it is happening in a decent cannabis soil.

I’m not familiar with Botanicare products. Overfeeding or underfeeding is not really relevant. Iron is provided in Big Bloom of the Fox Farm Trio. In Jack’s it is Part A that contains iron.

Your best bet will be to use all components of a balanced cannabis fertilizer. NPK and all of the micronutrients are all important for a healthy plant.

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Thanks for all the feedback! I assume the Pure Blend Pro is a balanced cannabis fertilizer.

Do you think i have the same issue w the smaller ones in the RDWC system? Are they in the beginning phases of the same deficiency?

Do all my numbers (PH, PPM, TEMP)seem to be right?

Is that just staining or something to be concerned about? They’re not slimy and they don’t smell bad


The color of roots is from Liquid Karma. You need to be using Silica Blast and Hydroguard as well. I use all Botanicare products as well. If i was you i would drain your system and start over with fresh. You need to mix everything in your remote res first. Silica, cal mag, grow, liquid karma then hydroguard in this order. I would also recommend only running your ec at 1.2-1.4 right now for the size of your plants. @HappyHydroGrower is really good with dwc ive learned alot from him. He may chime in with some other pointers


Great feedback! Thank you so much. I’ll try this. Do you think those are the beginning signs of a CAL mag deficiency? What are your thoughts on pH level? Am I good at 5.8?

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It is not a complete product. The contents are Nitrogen 3.0%, Phosphate 2.0%, Potash 4.0%, Ca 1.0% , Mg 0.5%, so all you are getting is weak NPK and a bit of cal/mag. Micronutrients are not contained in the product.

Possibly an early one, but keep in mind that new growth on cannabis will always be a lighter shade of green. If you are using the same product, then you are probably headed for an iron deficiency with those plants as well.

Temps and pH are okay. PPM is low.

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5.8 ph is perfect for hydro. I think you just have a nutrient imbalance atm. I would also recommend looking at botanicare pure blend tea to add to your mix 3ml gal for veg.

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@Cdizzle roots are white in hydro, so any color other than that is an indication of something…I see a deep brown here which is typical of a root fungus and it will be this color before you feel the slime…a root inoculant could be what you need…

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Thanks @CooterJuice
@Cdizzle If it were me in that condition. I would drain and run a 70/30 mix of water/peroxide solution in that bucket for about two hrs and then rinse well just incase it’s root rot.
Then find a reliable nute that’s proven to work for cannabis. Not saying yours is not.

Are you able to change nutes?
I would highly recommend Jack’s city limits or Jacks Tap with your water so high. You will hardly ever have any trouble. A lot of folks here use it. Hydro or soil. There are other products that do good as well but Jack is really stupid proof. If I can run it so can you. :+1:t2::v::sunglasses:


To me it looks like iron def