need help. second grow. deficiencys

Hey guys I'm running 4 (mainlined to eight colas) NYPD clones under a 400 hps. 7 gallon pots with pro mix hp. Fox farms dirty dozen, R/0 water with cal mag. Staying 74°to 78° with 50% humidity I'm on my 2nd week of flower and I noticed a calcium deficiency on a few of the old leaves . I flushed with 7 gallons each with 6.5 water I was getting a 5.5 runoff with 3000 ppm .I waited a week for the pots to dry and used half strength nutrients. To make a long story short I have bought a blue lab soil pH meter now and my pH is around 6.4 to 6.6 now( after an adjustment ) and 1200 ppm and they are still looking pretty crappy. Looks like a phosphorous deficiency now??? This all started from the bottom and is spreading upwards. Not sure what else to do! How long will it take for the deficiency to stop spreading to the newer growth

tmartin845013 said:

Hey guys I'm running 4 (mainlined to eight colas) NYPD clones under a 400 hps. 7 gallon pots with pro mix hp. Fox farms dirty dozen, R/0 water with cal mag. Staying 74°to 78° with 50% humidity I'm on my 2nd week of flower and I noticed a calcium deficiency on a few of the old leaves . I flushed with 7 gallons each with 6.5 water I was getting a 5.5 runoff with 3000 ppm .I waited a week for the pots to dry and used half strength nutrients. To make a long story short I have bought a blue lab soil pH meter now and my pH is around 6.4 to 6.6 now( after an adjustment ) and 1200 ppm and they are still looking pretty crappy. Looks like a phosphorous deficiency now??? This all started from the bottom and is spreading upwards. Not sure what else to do! How long will it take for the deficiency to stop spreading to the newer growth

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Need to get pics with hps off for better help brou!! Also 3000 ppm runoff its way to high, u might have a salt built up..

Sounds like salt buildup, acidifying the soil, nute lockout. It starts to appear in the leaves when my runoff hits 2500ppm. Next time water with water only and 100% runoff. Mild nutes next time.

flush for a day or so give them a break and then bring the nutes back in. keep them under 1000 for the rest of this grow. If you have a perfect grow going then id say 1200 or even higher but when things get tough its better to keep them on the low side..

Thanks for the replies guys! I had already flushed. Twice actually when I wrote this post. I also added mild nutrients. They are looking better. Seems to barely be spreading now if at all. My runoff is around 1100 . The only thing I'm having problems with is keeping my pH in my soil up to the correct levels even though I'm running 6.9 in and getting 6.0 to 6.3 out of the soil and with my blue lab soil pH pen. Then a few days later I check and it has already dropped back to 5.6 to 6.0. This is really confusing me and I'm trying to stay calm and fix it right. Only thing I have been adding is half strength nutrients and nectar of the gods Hurclean harvest with my nutes once a week roughly.

What do you guys make of this post? Should I worry about the pH fluctuations between watering or am I just chasing my tail?

tmartin845013 said:

Then a few days later I check and it has already dropped back to 5.6 to 6.0.

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How do you check a few days later?

Runoff ph is dubious. I use a $70 Control Wizard Accurate 8 to check my soil ph (rarely use it now that things are dialed in). The only realistically accurate way to test runoff is the NCSU Pour-Through Runoff Method. (google for it.). It's very tedious, which will illustrate why casual runoff measurements are dubious.

Soil ph rises as it dries, so if you're trying to raise your ph, be sure you're not watering too soon (trying to get higher ph liquid in there). That will hold the range which the plant experiences lower than it would otherwise experience. You'll contribute to the problem you're trying to solve.

The flush should be enough. Feed mild nutrients (at least less than you were feeding, which led to buildup). Monitor your runoff ppms to know if it's rising again. But, for now, I would make it priority #1 to let the soil dry completely (the container should be alarmingly light when you lift it). You want to get to pretty close to the point where the leaves wilt. I try to get 3-6 hours away from that.

OK well I have been checking my soil pH with my new blue lab 150$ soil pH probe i bought last week the reviews were great but is that not accurate? I have been checking the soil pH everyday with it in 4 different spots down in the root mass and taking the average of the 4 but according to it the pH seems to be dropping as they dry. I have been trying to get 20% runoff every time i water. Which is about 2 gallons per pot. And then it takes 6 days to get completely dry. Like I said I'm new to all this and open for suggestions.

tmartin845013 said:

OK well I have been checking my soil pH with my new blue lab 150$ soil pH probe i bought last week the reviews were great but is that not accurate?

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That should be good. I thought you might be using one of those $10 two-prong deals from Lowes. (Or, watering again, holding the soil wet.). I missed you saying "soil probe" in your first post.

tmartin845013 said:

And then it takes 6 days to get completely dry. Like I said I'm new to all this and open for suggestions.

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Next time add 30% perlite to the soil. I like it when it dries in 2-3 days. If you were using an organically amended, composted soil maybe a heavier/richer/slower drying soil would be good. But, for most people, more rapid drying is better.

What soil do you use? (It sounds like it could be FoxFarms. From the pictures I've seen, it looks too heavy/rich, not enough perlite for faster drying.).

This is what I do.

I wouldn't chase your ph. Your plant looks fine. Let it do its thing. Amend 1tbsp/gal dolomite next time (plus perlite).

You could topdress some dolomite into your soil and water it in. About 1tbsp. But, it takes 10 days to do anything. But, the risk is that you'll water sooner than you should just to treat the ph, which may not be a problem. Don't kill it with kindness. Stand back. All I see is nute burn, which resulted in salt build up in the soil, apparently.

You think that looks like nute burn? It started a few weeks ago on the very lowest fans and has spread all the way up almost after i did that flush till I got to 1000 ppm. i thought it was a deficency from lockout. I'm using Pro Mix HP and strong pots (fabric) . so you would suggest just letting them dry up mostly before watering and add topdress with dolomite which will bring my pH up correct?

When I used Pro-Mix HP+Myco, and added 25% perlite (I've forgotten how much I added now.). If you look at that link in the previous reply, you'll see I add some soil to create a very light soil. It's been working well. The reason I mention it is that you're using FF nutrients which I don't think is ideal for soilless. It would probably work better with soil. When I grew soilless, I used GH Flora 3-part which is hydro (more suitable for soilless).

It might be early K def. That would be pH related. I can't say I see P def.

But, yes, you should let them dry. If I were you, I would wait until it's so dry the leaves droop. They'll bounce back within 30 minutes after watering. It's not desireable to let them get that dry. But, it can be useful to do it just to see what "too dry" feels like when you lift the container. Then you'll know how dry it should get. (You're trading one stress for what could be an ongoing stress if you aren't letting them dry enough. It really should be alarmingly light.). You'll have to water slowly because when Pro-Mix dries that much, it can resist water. That's another reason not to let it reach the wilting level (except to teach yourself what the weight can feel like a few hours before wilting).

It wouldn't hurt to topdress with dolomite. But, I bet you're not letting the medium dry enough.

Don't worry too much. You're learning. Your next grow you should amend 1tbsp/gal dolomite before planting. Use a hydro nutrient if you want to do soilless. Else, create a more soil'y medium like I do. I think your problem is the nutrients designed for soil, but not having soil.

tmartin845013 said:

Promix HP is soil.?

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It's soilless. Just peat, perlite, dolomite and myco (if you got the HP+Myco. They've exploded their product line into absolute confusion, IMO). The pH should be 5.8-6.0 in veg, 6.0-6.2 in flower. It's kind of between hydro and soil.

Oh OK I understand. Damn, right on man! So much to learn. What medium do you use or recommend ?

tmartin845013 said:

Oh OK I understand. Damn, right on man! So much to learn. What medium do you use or recommend ?

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Look at the link I gave you 5-6 posts above.

I think they are looking pretty good now. My pH all checked out at around 6.2 so something is working. They don't look as bad when the're not under the HPS. they are getting very dry all except one of them so I'm going to wait one more day. What pH solution should I use? 6.4 ish?

Don't worry about run off pH, you will chase your tail.

3000 run off. That's a problem. Salt build up. Flush and water only for a few waterings.

Also make sure you got good run off if pushing the ppms hard.

Alright guys I'm completely frustrated now. Everything was looking much better Saturday and the pots were completely dry. I checked the soil pH with my probe and they all checked out around 6.5 so I was shooting for a 5.8 end result for my pro mix so I added 5.9 and mild nutrients with a soil pH of 5.8 to 5.9 and today they look like shit again. . . I and my pH is checking out around 5.4 wtf? Feel like I'm gonna lose these fuckers

Here's a little closer pic

The only thing I changed is this. I use R/O water because I have well water and the ppm's alone are 750 so here's what I did. I wanted to get away from cal-mag and pH up so I used 1 3/4 gallon R/O and the rest well water and it came out just at 5.9 with no added buffers besides nutrients at less than 1/2 strength. Do you think this is part of the problem?