Nute Burn with the Lucas Method?

[sneekymofo]

Hello All,

First, thanks to everyone on this site....the info provided has helped me on more than one occasion!

The situation:
Hydro: DWC, 5 gallon bucket, 2 5 inch airstones, hydroton
Cabinet: 2x2x5 Flowering Area
Light: 150w HPS, 6-8 inches from tops (hand comfortable)
Nutrients: GH 3-part, using Lucas Formula 0-8-16 (PPM:1200, pH 5.0-5.5)
Temps: 72-80 (+0-8 deg over ambient)
Water: Aged tap, PPM < 70
Air: Venting through DIY carbon scrubber with 175 CFM fan, 1 circulating fan underneath canopy (won't fit above...), passive intake.
Method: ScrOG; daily top-off with pH adjusted H2O, drain weekly, flush bi-weekly with Clearex.
Genetics: Unknown (guesses are appreciated!) Rhino?
Age: Beginning 6th week of flower; clones from bonsai mother 1.5 years old
I think that's all the basic information....:thumbsup:

Basically, this is my second attempt at this strain. I started with full-strength nutes from GH and practically burned them up around the same week. Limped through to a sub-standard harvest of 70g. I learned (or so I had thought), then switched to Lucas Formula hoping to find a magic bullet. Plants did great through 0-5-10 (veg 4 weeks), but starting showing signs of significant burn (I think) by the beginning of last week. I Clearex flushed, trimmed the crispy tips of affected leaves, and continue having problems. I have sinced backed down to 75% of Lucas (PPM 910 [.7] now), but seem to be continuing to have the same issue. I am currently considering dropping to 50% of Lucas which would put PPM around 650-700 or so....or maybe switching back to 0-5-10 as suggested for "low-intensity lights" even though I am using a small HID. I'm worried about "starving" them when I want them putting on weight.

Based on the attachments:
1. Is this nutrient burn, or some sort of definiency?
2. Do I need to back way off the nutrients using such a small light (I've seen suggestions for low-intensity lights....)?
3. Do I need to adjust nutrient levels since this is a DWC (vs. NFT, ebb-flow, etc.)?
3. I know this may be a genetics problem (this hermies pretty easy too), but I don't want to waste a bunch of money on genetics if I'm setting them up for failure too.

Thanks for any help!!!

[SpaceNeedle]

You know,.... You are driving in the dark when you are trying to grow hydroponically and not use an EC/PPM meter. Those pics could be a burn, and if they are, they are the worst I've seen. Spend 30 or $40 on a meter and then give us the PPMs of your nutrient. IF you are giving your plants full nutes when they are very young you are asking for disaster.

[sneekymofo]

I use a BlueLab, it's just not super accurate. It bounces between numbers a lot, so I sometimes have to estimate. At 75% of Lucas, I read at 910 (an average of the 2 readings). I was estimating 50% Lucas because I wasn't sure since I hadn't done it yet. I'm guessing that I shouldn't continue to have problems with such a low PPM now. As for age, I flipped to 12/12 at 4 weeks, but the clone is much older. I also "walked" up to 1200, by going with 50% the first week, and 75% the second week of flower. Was that too fast? I have limited space in the cab, so I flip to flower fairly early....

[Daddynobucks]

try 1-4-8 per gal plus 2ml CaMg and dilute to two gals

what I see there is nuit. lockout from improper mixing,been there and got the T-shirt, always mix each with a volume of water befor combining in the correct order which is 4ml Micro,1-2ml CaMg,1ml grow,8ml bloom move Ph to 5.6-5.8
You would do better with a T-5 floresent, low wattage sodiums aren't really the right color temp.
try a new battery in your meter
hope this helps
Daddy

[tinytoon]

Ding Ding Ding!!! Daddy wins a cupie doll!!! PH to low will cause lockout just as Daddy says. If PH is wrong it will cause many problems and make you run around in circles trying to figure out wtf went wrong. Correct the base problem and then go from there. Daddy says 5.6-5.8 and I run my 3 at 5.7-6.0. Happy growing :jointsmile:

[AquaponicHerb]

personally I don't follow any of that. I use 1/4 to 1/2 strength nutrients and I use over 150 gallons of water. This way the plants get whatever nutes they need and I will never need a meter or get nute burns. You see the plant takes what it needs.

I don't even know if this works but its based on botanical data. try at your own risk :P

[sneekymofo]

My pH reads at 5.5 - 6.0 currently. I test it when I top off and I test when I drain. It fluctuates, but so far within an "acceptable" pH range. I also always put two gallons of water in my mixing container, mix micro in with a gallon of water, then bloom with a gallon. I had heard that mixing them directly could cause an issue so I avoid it like the plague. My BlueLab is new (4 months) but I'll try replacing the battery. I wouldn't imagine that would be the issue, but I'll try anything at this point. I've thought about just never going above 1/2 strength nutes for this strain, but I was afraid I'd starve it to death.....

[tinytoon]

As for the mixing you can do that in 1 jug np. Micro 1st then Grow (if using) then Bloom. When they say dont mix the 2 together they are talking out of water. Dont put micro in a container and add grow or bloom directly to this without water.

[Daddynobucks]

Daddy says 5.6-5.8 and I run my 3 at 5.7-6.0. Happy growing :jointsmile:


I think the diff in preferred Ph range is due to Aeroponic root spray vs. DWC.

Daddy

[tinytoon]

/agree Daddy. DWC doesnt seem to mind if I get up to 6.0 but the Ebb&Grow system seems to do better if not above 5.8 :thumbsup: