Update on slow growth

I have eight plants that are about four weeks old. They are under four, 6500K, 65w CLF's on a 18/6 lighting schedule. I've fed them 1/4 strength Jack's Classic after they got some true leaves. I've used Superthrive sparingly. The feedings have taken place about once a week. Water pH (and ferts) are around 6.0. I water them with room temperature water.

The plants are in Black Gold Seedling Mix. I may have over watered them early in their lives but I'm not doing so anymore. The relative humidity is around 60% and soil temperatures range from 74F (lights on) to 65F (lights off.) There's a small fan in the grow box along with a humidifier.

When the sun is shining I put them in a very sunny room for a few hours. The soil temperature pops up to about 80F when they are in the sun.

There are three varieties: Cheeseberry Haze (50% Sativa) - Candy Kush (Indica feminized) and Jackberry x Shack (Indica feminized.)

Two of the plants were sprouted in the aforementioned seedling mix. The others in wet paper towels.

While all of the plants seem to be growing very slowly to me, some of them appear to be static or worse.

Attached are some photos. Tell me what you guys think.

Thanks a lot.

Earlier we talked about how you use tap water and that you don't know the quality of your water, and especially the TDS. Did you take any steps in that regard?

IMO, that's a significant variable in your grow. The only time I've had stunted growth like that was when I used tap water on my first grow. I wasn't aware of the significance of TDS levels. My tap water is 600-750. It doesn't leave much room for 500ppm of nutrients. (Or, it competes with the ppm of nutrients, locking out nutrients. I'm not sure how to explain it. But, it stunted my seedlings just like yours.).

I'd lay off the "extras" like SuperThrive. You want to have a no-frills grow where the basics are correct.

- You've got good nutrients.
- You've got what appears to be good soil.
- I'm not a fan of CFL. But, they won't cause the stunted growth you're having. (You might add a warm CFL. Like, 3 cool to 1 warm. But, that shouldn't cause what you have.).
- Not sure what your ph is, but it shouldn't matter much in soil. At worst you'd have a deficiency or two.
- Your water is unknown.

My money is on that last one. As I said in the previous post, if you don't have a PPM meter (if you have to shoot into the dark), I would mix tap and RO 50/50. RO by itself isn't perfect (you'd need to add some calmag to make up for the lost minerals). Mixing 50/50 would be a better "bet" than using tap alone.

But, eventually you need a TDS meter and mix tap/RO to get 150'ish PPMs. Or, use RO and calmag to get similar.

It's very likely that well water is high in minerals (ppm).

az2000 said:

Earlier we talked about how you use tap water and that you don't know the quality of your water, and especially the TDS. Did you take any steps in that regard?

IMO, that's a significant variable in your grow. The only time I've had stunted growth like that was when I used tap water on my first grow. I wasn't aware of the significance of TDS levels. My tap water is 600-750. It doesn't leave much room for 500ppm of nutrients. (Or, it competes with the ppm of nutrients, locking out nutrients. I'm not sure how to explain it. But, it stunted my seedlings just like yours.).

I'd lay off the "extras" like SuperThrive. You want to have a no-frills grow where the basics are correct.

- You've got good nutrients.
- You've got what appears to be good soil.
- I'm not a fan of CFL. But, they won't cause the stunted growth you're having. (You might add a warm CFL. Like, 3 cool to 1 warm. But, that shouldn't cause what you have.).
- Not sure what your ph is, but it shouldn't matter much in soil. At worst you'd have a deficiency or two.
- Your water is unknown.

My money is on that last one. As I said in the previous post, if you don't have a PPM meter (if you have to shoot into the dark), I would mix tap and RO 50/50. RO by itself isn't perfect (you'd need to add some calmag to make up for the lost minerals). Mixing 50/50 would be a better "bet" than using tap alone.

But, eventually you need a TDS meter and mix tap/RO to get 150'ish PPMs. Or, use RO and calmag to get similar.

It's very likely that well water is high in minerals (ppm).

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I appreciate the effort you've put into trying to help me az.

My water pH is around 6.0. Out of the tap it was 7.5. I adjusted with a tiny amount of white vinegar.

I can switch to bottled water. Poland Spring water is very low in TDS. If you think this is worthwhile, I'll add some cal mag as you suggested.
If I switch to bottled water, should I flush my plants with it to drive out the old tap water remnants ? Obviously I'll check the water's pH before doing so.

After the flush (if needed) should I just use water and calmag for a while ? No ferts ?

I have two 600 watt HID lamps but I'm waiting until my plants get bigger (if ever.)

Again, thank you for your attention and clear instructions.

can't beat the price it works have one of each

http://www.ebay.com/itm/New-LCD-Digital-TDS3-TDS-Meter-Filter-Pen-Temp-PPM-Tester-Stick-Water-Purity-/111618042648?pt=LH_DefaultDomain_0&hash=item19fcf42b18

http://www.ebay.com/itm/New-LCD-Digital-TDS-Meter-Tester-Water-Quality-ppm-Purity-Filter-With-battery-/290615186347?pt=LH_DefaultDomain_0&hash=item43aa03d3ab

If it were me, I'd spend the $20 on the HM TDS meter mentioned in the other thread. In the meantime I would mix 50/50 tap and RO. (I'm not sure how you know the TDS of your bottled water without a meter. But, as long as you know what it is.). I'd go this direction. If your tap water is acceptable, cutting it 50% won't change it much. If it's unacceptable, it will make a significant difference. IMO this would be better than buying calmag which you may never need. (Spend the money on a TDS meter and know what you're dealing with.).

az2000 said:

If it were me, I'd spend the $20 on the HM TDS meter mentioned in the other thread. In the meantime I would mix 50/50 tap and RO. (I'm not sure how you know the TDS of your bottled water without a meter. But, as long as you know what it is.). I'd go this direction. If your tap water is acceptable, cutting it 50% won't change it much. If it's unacceptable, it will make a significant difference. IMO this would be better than buying calmag which you may never need. (Spend the money on a TDS meter and know what you're dealing with.).

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Poland Spring's bottled water is 21 PPM TDS. I'll try mixing 50/50 with my tap and not bother with the calmag.

Should I skip feeding my plants for a while ?

Again, thank you.

az2000

I just ordered the meter you suggested.

Camo Hat said:

Poland Spring's bottled water is 21 PPM TDS. I'll try mixing 50/50 with my tap and not bother with the calmag.

Should I skip feeding my plants for a while ?.

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I would feed the same amount you've been feeding. I would mix enough to get about 30-50% runoff (30-50% of the volume of soil container) to displace what may be deposits of whatever's in your tap water. This is touchy because I wouldn't do high runoff with seedlings. But, yours are (technically) in aggressive veg now (by age).

From everything you've described about your environment, I'd give 10 to 1 odds that it's your water. Everything else sounds ok. Maybe not optimal (for example, the CFLs are the weakest link I can see). But, as far as drastically stunted growth, water is by far the likely culprit.

It could be you're not feeding enough. But, going into aggressive veg I'd expect to see deficiencies not just stunted growth. You can't slow down a plant by underfeeding it. (I've tried. All I got was generalized deficiency, blotchy leaves, mg def, ca def, N def, etc.). At this point in their life they *want* to grow.

It's possible to have a slow-growing runt, or a plant that's stunted for some strange reason like the root encountered a large piece of material in the soil and wasted some energy dealing with it. I get 1 of those out of every 6-10 plants. But, every one of them. It reminds me of when I used 600ppm tap water on my first grow.

Do you have a gram scale? How much are you feeding by weight? (Remind me again, is it Jack's All Purpose?). 2 grams of All Purpose should produce about 480 PPM. That sounds sane to me. Being on the early side of veg, I'd do a tad less, like 1.7g (for 410ppm).

Be sure to let the soil dry adequately. The ph rises as it dries, exposing a wider range of nutrient availability. It might be ok to do it a little sooner this one time to get nutes into the soil (without what we believe to be too much useless salts from your well water). But, holding the soil too wet continuously can cause problems.

az2000 said:

I would feed the same amount you've been feeding. I would mix enough to get about 30-50% runoff (30-50% of the volume of soil container) to displace what may be deposits of whatever's in your tap water. This is touchy because I wouldn't do high runoff with seedlings. But, yours are (technically) in aggressive veg now (by age).

From everything you've described about your environment, I'd give 10 to 1 odds that it's your water. Everything else sounds ok. Maybe not optimal (for example, the CFLs are the weakest link I can see). But, as far as drastically stunted growth, water is by far the likely culprit.

It could be you're not feeding enough. But, going into aggressive veg I'd expect to see deficiencies not just stunted growth. You can't slow down a plant by underfeeding it. (I've tried. All I got was generalized deficiency, blotchy leaves, mg def, ca def, N def, etc.). At this point in their life they *want* to grow.

It's possible to have a slow-growing runt, or a plant that's stunted for some strange reason like the root encountered a large piece of material in the soil and wasted some energy dealing with it. I get 1 of those out of every 6-10 plants. But, every one of them. It reminds me of when I used 600ppm tap water on my first grow.

Do you have a gram scale? How much are you feeding by weight? (Remind me again, is it Jack's All Purpose?). 2 grams of All Purpose should produce about 480 PPM. That sounds sane to me. Being on the early side of veg, I'd do a tad less, like 1.7g (for 410ppm).

Be sure to let the soil dry adequately. The ph rises as it dries, exposing a wider range of nutrient availability. It might be ok to do it a little sooner this one time to get nutes into the soil (without what we believe to be too much useless salts from your well water). But, holding the soil too wet continuously can cause problems.

Click to expand...

Yes. Jacks Classic all Purpose it's 20-20-20. I don't have a gram scale. I've been mixing the Jacks at 1/4 recommended. I use the little spoon that comes with the Jack's.

How's this for a plan ?

I'll mix some Jack's (50% strength) with the 50/50 Poland Springs and Tap water. Adjust pH to 6.0 or so and pour enough into my plants to get a 50% run off.

I won't water or feed them again until they dry out a reasonable amount.

Thanks again.

has anybody discussed white vinegar as your pH down method? i've read lemon juice is better. better yet would be real hydro pH up and down. just a thought.

or switch to floranova bloom as the Lucas formula and your pH will be right where it needs to be if you use RO water with it

rkymtnman said:

has anybody discussed white vinegar as your pH down method? i've read lemon juice is better. better yet would be real hydro pH up and down. just a thought.

or switch to floranova bloom as the Lucas formula and your pH will be right where it needs to be if you use RO water with it

Click to expand...

The amount of vinegar required to lower a gallon of water with a pH of 7.5 to 6.0 is miniscule. On the order of two to three drops.

Vinegar is Acetic Acid and Lemon Juice is Citric Acid. They are chemically similar.

I appreciate the input.

Camo Hat said:

Yes. Jacks Classic all Purpose it's 20-20-20. I don't have a gram scale. I've been mixing the Jacks at 1/4 recommended. I use the little spoon that comes with the Jack's.

How's this for a plan ?

I'll mix some Jack's (50% strength) with the 50/50 Poland Springs and Tap water. Adjust pH to 6.0 or so and pour enough into my plants to get a 50% run off.

I won't water or feed them again until they dry out a reasonable amount.

Click to expand...

That sounds good. I haven't used Jack's so I can't comment on how strong half strength is. You're really talking about volume because the label recommends volume measurements. I don't know how that relates to weight.

Regarding ph. If you're going to ph your nutrients, I'd do 6.5. However, I recall you posted something about using vinegar and baking soda. I would probably not ph if that's all I had available to me. In soil, phing your nutrients isn't too important. But, it's not a bad idea to do it as a new grower to rule out that variable. (However, vinegar and soda are their own variables.).

What is the ph of your nutrient solution? (It may be significantly different than when you used tap water alone.). Have you calibrated your ph pen?

Camo Hat said:

The amount of vinegar required to lower a gallon of water with a pH of 7.5 to 6.0 is miniscule. On the order of two to three drops..

Click to expand...

That's the reason people say phing nutrient solution for soil is pointless. The soil has more buffers in it to withstand ph change than the water does. If it only takes 2-3 drops, the soil will be buffered much more than that.

Mix some now with 50/50 tap and RO water, and 3/8 strength Jack's (splitting the difference between 1/4 and 1/2 strength). See what the ph is with less well water. If the well water is hard and mineralized, the ph now may be different. If it's in the 6.0-7.0 range, I don't think I'd adjust it.

It would be interesting to know the ph of your runoff. As an individual reading this isn't too accurate. But, as a trend it can be useful. (When you have the TDS meter you'll want to measure your runoff ppms too.). This will help you know if you need to ph the nutrient solution (also if you're overfeeding).

I'd eliminate vinegar and baking soda as variables. But, post the PH of your nutrient solution when created with 50/50 tap and RO. 2-3 drops shouldn't hurt. (I'd never use baking soda.). But,at that rate it shouldn't help much either.

Camo Hat said:

The amount of vinegar required to lower a gallon of water with a pH of 7.5 to 6.0 is miniscule. On the order of two to three drops.

Vinegar is Acetic Acid and Lemon Juice is Citric Acid. They are chemically similar.

I appreciate the input.

Click to expand...

true they are similar but they don't have the buffers that hydro up and down have. have you pH'd your runoff? is your runoff the same as what is going in?

rkymtnman said:

true they are similar but they don't have the buffers that hydro up and down have. have you pH'd your runoff? is your runoff the same as what is going in?

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I imagine the buffers are different but that's getting too technical for me. I've been out of school a long time.

I've never checked my runoff pH. I will when I do the next water/feeding tonight.

Thank you.

az2000 said:

That's the reason people say phing nutrient solution for soil is pointless. The soil has more buffers in it to withstand ph change than the water does. If it only takes 2-3 drops, the soil will be buffered much more than that.

Mix some now with 50/50 tap and RO water, and 3/8 strength Jack's (splitting the difference between 1/4 and 1/2 strength). See what the ph is with less well water. If the well water is hard and mineralized, the ph now may be different. If it's in the 6.0-7.0 range, I don't think I'd adjust it.

It would be interesting to know the ph of your runoff. As an individual reading this isn't too accurate. But, as a trend it can be useful. (When you have the TDS meter you'll want to measure your runoff ppms too.). This will help you know if you need to ph the nutrient solution (also if you're overfeeding).

I'd eliminate vinegar and baking soda as variables. But, post the PH of your nutrient solution when created with 50/50 tap and RO. 2-3 drops shouldn't hurt. (I'd never use baking soda.). But,at that rate it shouldn't help much either.

Click to expand...

I mixed the Jack's as you suggested and the pH is 6.2. (My meter is calibrated) I won't adjust the mixture as you suggested.

I'm going to do the water/feed thing tonight. I'll do most of my plants but not all of them.

Much appreciated.

Camo Hat said:

I'm going to do the water/feed thing tonight. I'll do most of my plants but not all of them.

Click to expand...

That's a good idea. Treating dirferent plants differently is something I forget to do. You can discover more things faster that way (if you take good notes and don't get confused later about what you did).

Another way to get some good experience is to grow 12/12 from seed. You can have a perpetual harvest, where you remove a plant every couple weeks, add a seedling at the same time (and have a couple plants somewhere in between). Instead of growing 6-10 plants all at once and waiting 3-4 months before applying what you learned, you can apply what you learned every couple weeks. You can get a couple year's skill in 6-12 months. But, it takes good record keeping, A methodology.

6.2 sounds good. Track your runoff ph and ppms.

I bet they'll green up and take off. If you let the nutrient solution sit, it will probably rise in PH. You can see this by leaving some tap water on the countertop. After a couple days mine will rise quite a bit. Has something to do with water absorbing carbon from the air, creating carbonic acid. I don't know, but I see it consistently with my tap water.

az2000 said:

That's a good idea. Treating dirferent plants differently is something I forget to do. You can discover more things faster that way (if you take good notes and don't get confused later about what you did).

Another way to get some good experience is to grow 12/12 from seed. You can have a perpetual harvest, where you remove a plant every couple weeks, add a seedling at the same time (and have a couple plants somewhere in between). Instead of growing 6-10 plants all at once and waiting 3-4 months before applying what you learned, you can apply what you learned every couple weeks. You can get a couple year's skill in 6-12 months. But, it takes good record keeping, A methodology.

6.2 sounds good. Track your runoff ph and ppms.

I bet they'll green up and take off. If you let the nutrient solution sit, it will probably rise in PH. You can see this by leaving some tap water on the countertop. After a couple days mine will rise quite a bit. Has something to do with water absorbing carbon from the air, creating carbonic acid. I don't know, but I see it consistently with my tap water.

Click to expand...

I'd like to send you a bag of buds but alas, The Federal Government has no sense of humor.

az2000 said:

That's a good idea. Treating dirferent plants differently is something I forget to do. You can discover more things faster that way (if you take good notes and don't get confused later about what you did).

Another way to get some good experience is to grow 12/12 from seed. You can have a perpetual harvest, where you remove a plant every couple weeks, add a seedling at the same time (and have a couple plants somewhere in between). Instead of growing 6-10 plants all at once and waiting 3-4 months before applying what you learned, you can apply what you learned every couple weeks. You can get a couple year's skill in 6-12 months. But, it takes good record keeping, A methodology.

6.2 sounds good. Track your runoff ph and ppms.

I bet they'll green up and take off. If you let the nutrient solution sit, it will probably rise in PH. You can see this by leaving some tap water on the countertop. After a couple days mine will rise quite a bit. Has something to do with water absorbing carbon from the air, creating carbonic acid. I don't know, but I see it consistently with my tap water.

Click to expand...

I did what we discussed above. My runoff water pH was 5.1.

Plants are back under the lights. I'll keep you informed.

THX.

Camo Hat said:

My runoff water pH was 5.1.

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That's pretty low. But, runoff ph is subject to some variables that make it nebulously connected to actual soil ph. In my case (my soil, my nutrients, my watering style) I start having nute lockout as runoff goes below 5.2. My runoff ppms are about 2500 at that point. Normally they'll be 800 in veg, 1000 in early flower and 1100-1200 in late flower. If it gets up to 2500, then I'm overfeeding, not getting enough runoff. (When I was double what I do now, I'd hit 2500 in early flower.). This is a reason why the trend is useful. Monitor ph and ppm trend until you get things dialed in. Once they're dialed in you don't need to mess with it. I spot check occasionally just to remind myself what the numbers should look like.

If you want to see why runoff ph is nebulous, google for NCSU Pour-Through Method. The tedium of that method suggests why casual watering (soak times and runoff quantities) is unreliable.

However, you're using a good soil. It should be too early in your grow to have salt buildup. On the other hand, if your well water is high in TDS, then you could have salt build up because there'd be a lot of stuff in the soil the plant can't consume. The 30-50% runoff should help with that. You should keep doing 20% or more. (After you dial things in you can reduce that if you think it's wasteful. I tried low runoff. But, 20% runoff seemed like cheap insurance. I can feed a little stronger since the runoff pushes out unused salts. It's like putting a fresh plate in front of the plant instead of making it finish what was on the last plate.).

Also, it could be partly a result of not letting the soil dry before feeding.

Let it dry very well this time. The container should feel very light. I wouldn't go this far now, but you can wait until the leaves droop to learn how light the container feels. The leaves will bounce back 20 minutes after watering. That's a good way to learn how it feels when it's too dry.