Lucas formula question

So i'm running an nft system, my plants are about 7” tall. I'm using the Lucas formula, growing Kushberry. The system, the Lucas formula and the strain are all new to me. I'm used to flood and drain with a full nute line. I'm using r.o water. Question : my plants are yellowing and I can't figure out if its nitrogen or do I need Cal/mag? I'm only using 4-8 and it seems i'm getting a bit of nute burn on the tips. I added 1/2 strength Cal/mag but if i'm getting nute burn at 600 ppm (.5 scale) what should I do? I know you guys need pictures. Lights aren't on yet. I'll get them asap. But until then, any suggestions? Thanks

Which nutrients are you using? You say your using a full line and also Lucas... It's happened to me with with Lucas and young cuts I had to flush than decrease amount of nuts for a bit until they started looking better than began upping it. You shouldn't need cal mag with the Lucas formula, so my guess is a lock out due to a hot mix

Ok, so here are some pictures. I can't find net pot covers so I had to use rockwool covers, that's why it looks ghetto..

Lucas is only bloom and Micro ..

but your saying you have both nuts burn and yellowing and in need of Nitrogen and/or cal/Mg ? I like to see some pictures please ..

I'm only using the gh micro and bloom 4-8 here is the nft system i'm using, sorry. Just to clarify I was trying to say, i'm using Lucas now (grow and bloom) but its new to me because i'm used to using a full line in the past.

marc88101 said:

I'm only using the gh micro and bloom 4-8 here is the nft system i'm using, sorry. Just to clarify I was trying to say, i'm using Lucas now (grow and bloom) but its new to me because i'm used to using a full line in the past.

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how much nutes are you using? I don't understand "gh micro and bloom 4-8" lucas formula is 8ml micro and 16ml bloom. I don't have problems with it but I use pro-mix I really don't see a difference from when I was using technaflora's nute line.

I'm using 4ml of micro and 8ml of bloom. It says fill strength is 8-16 but if i'm getting nute burn at 4-8 won't 8-16 fry my plants? When do you go full strength?? From clone?

I find NFT doesnt use as high EC as a flood system however I use lucas and i ran it about 900ppm this looks like a hybrid nft system. So.. what you got going on in there some sprayers on some timers or constant flow? mybe its drying out inside and giving you salt build up? only thing i can think of

I go by ppm along with reading the plant until I increase my nutrients. I wait until ppm is either staying roughly the same, or decreasing before I start upping my nutrients.they say Lucas is 8-16 as long as your under HID but I have a sweet skunk that won't let me do that, I have to start off very slow. I really only hit the 8-16 with that particular one shortly after flip. My other gods gift can tAke 8-16most of their lives

KingstonR said:

I go by ppm along with reading the plant until I increase my nutrients. I wait until ppm is either staying roughly the same, or decreasing before I start upping my nutrients.they say Lucas is 8-16 as long as your under HID but I have a sweet skunk that won't let me do that, I have to start off very slow. I really only hit the 8-16 with that particular one shortly after flip. My other gods gift can tAke 8-16most of their lives

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From looking at my pictures what would you say is the issue? Do your think could handle 8-16?

marc88101 said:

I'm using 4ml of micro and 8ml of bloom. It says fill strength is 8-16 but if i'm getting nute burn at 4-8 won't 8-16 fry my plants? When do you go full strength?? From clone?

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I use the three part for veg then in flower I use lucas at a little more than half strength with a little bit of the veg nutes at first and add a little more micro and bloom each time for the first 2 weeks then I start using full strength lucas with no veg nutes and I haven't got nute burn from it yet but I'm only on my second run with lucas formula.

but that could be your problem lucas formula is more for flower and it looks like your still vegging.

bluntmassa1 said:

I use the three part for veg then in flower I use lucas at a little more than half strength with a little bit of the veg nutes at first and add a little more micro and bloom each time for the first 2 weeks then I start using full strength lucas with no veg nutes and I haven't got nute burn from it yet but I'm only on my second run with lucas formula.

but that could be your problem lucas formula is more for flower and it looks like your still vegging.

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yep, i'm in veg, so do you think I shoulc use the gh for early veg? Using the 3 part, it has early veg at 900 ppm. Do you think that's to high fot the size of my plants?

ringlead3r said:

I find NFT doesnt use as high EC as a flood system however I use lucas and i ran it about 900ppm this looks like a hybrid nft system. So.. what you got going on in there some sprayers on some timers or constant flow? mybe its drying out inside and giving you salt build up? only thing i can think of

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My feeding cycle is 1 hour on..15 minutes off, lights on.

I thought the Lucas formula was the way to go until if found this thread...it uses GH Flora Nova Bloom only in place of Lucas, start to finish. About the same as Lucas but better. It has a little N and it's buffed with citrus acid. I know I've posted this link in other threads, but here it is again... The first 25 pages explains it all better than I can, plus it has picturtes... https://www.rollitup.org/grow-journals/344359-pineapple-express-g13-labs-seed.html I'll probably catch some shit for posting it again...

most likely if your getting nute burn at 650 its ur system

check your cal/mag it could have chelated iron and nitrogen in it which could be causing the nute burn. chelated nutes always run hot because the roots have an easier time intaking them so less is more!


what brand of cal/mag are you running and how much?

Fuck it! I'm over the Lucas formula for veg, maybe I'll try it in flower. I just changed out my Rez, did a flush. I'm going to try 7-5-3 grow, micro, bloom. It seems like a sensitive strain, the ppm is 570. I knew I should have stayed with the Hindu Kush, but i'm bored with it! I wanted something new! I guess I got what I asked for. Anyone grow Kushberry? Its a finiky little girl!

I was using gh Cal/mag..hopefully 7-5-3 I won't need it..although I am using RO water and I hear gh 3 part is light on Cal/mag

....been running the Lucas formula for years, in veg and bloom....never had a problem, idk what's up bro.

The formula of 4-8 is half of the bloom regimen, and those plants look to be in veg. You could have just added some Grow to your res, but it's best to change the res. The Grow has more ammonia Nitrogen than nitrate Nitrogen, and the Micro has mostly nitrate Nitrogen, so adding both kinds may be just what your plants need now. During flowering, you can reduce or cut out the Grow again.

With nft supplying a constantly flowing source of nutes, I've found that it's best to keep the ppms low, so it sounds like you have a good recipe. Also keep a close eye on the temp of the soup, anything above 75 means nasties will grow.