Low ph in coco

[Zmh]

Hello

Day temp: 24-25c
Night temp: 19-21c
RH: 40% ish

DTW coco with automated feeding 5 times a day. I gave them about 1,4-1,6 EC early flower, but noticed some salt buildup so I lowered the EC a little. Giving them about 1,2EC now. PH 5,8-6.

About a week ago I noticed that one of my plants had some minor nute defiency. My first thought was calcium def cuz of the rust spots on the leaves. I'm using coco nutrients so haven't been giving them any calmag, but after I noticed the defiency I've been giving them some along with the base nutrients.

It got slightly worse the last week and I also noticed my runoff pH measured like 4ph so I guess my coco is acidic and I might have a lockout? Even after a 20L flush with 6,5ph my run off is still very low.

It's only my second grow so I'm not quite sure what to do next, I'm thinking about lowering the EC a little and maybe adjust the PH in my resorvar to above 6 but would be nice with some other input.

Week 7 in flower ish. I have 3 other strains on the same setup that are doing fine so don't wanna do anything to drastic.

 

[twentyeight.threefive]

What exactly are you feeding them? What nutrient line and amounts of each?

What did you flush 20L of? Water or nutrients?

 

[ttystikk]

EC 1.2 is pretty low and could easily lead to the issues you're seeing. Your temps are also low and that slows metabolism, your plants will want higher EC.

Always flush with nutrient solution, never straight water.

Feeding 5x per day seems like a lot unless your coco pots are tiny. You want the substrate to get light between watering.

 

[Zmh]

I'm using T.A/GHE duo coco grow

DualPart® Coco - Terra Aquatica

Uniquely amongst leading brands, T.A. DualPart® Coco doesn’t need additives for success from seed to bloom : other coco specific […]

www.eurohydro.com

I did flush with strait water, but I gave them a normal feed after flush.

First 5 weeks
30ml grow and 60ml bloom in 60L resorvar @ 1,4-1,6EC

After I noticed the def
20ml grow, 40ml bloom and 30ml cal mag @ 1,2 EC

I know it's low, but I thought extra feedings made up for that.

I thought 24C was optimum for mid/late flower? I could easily raise the temps abit

 

[ttystikk]

I'm using T.A/GHE duo coco grow

DualPart® Coco - Terra Aquatica

Uniquely amongst leading brands, T.A. DualPart® Coco doesn’t need additives for success from seed to bloom : other coco specific […]

www.eurohydro.com

I did flush with strait water, but I gave them a normal feed after flush.

First 5 weeks
30ml grow and 60ml bloom in 60L resorvar @ 1,4-1,6EC

After I noticed the def
20ml grow, 40ml bloom and 30ml cal mag @ 1,2 EC

I know it's low, but I thought extra feedings made up for that.

I thought 24C was optimum for mid/late flower? I could easily raise the temps abit

How much runoff are you getting? You want at least some and preferably around 15% by the end of the day. That will keep salts from building up.

 

[Zmh]

How much runoff are you getting? You want at least some and preferably around 15% by the end of the day. That will keep salts from building up.

Since I have 4 different strains on a automated watering system it's not so easy to measure individually. But I do get runoff every watering. I would guess 1-2L run off from all plants each watering.

 

[ttystikk]

Since I have 4 different strains on a automated watering system it's not so easy to measure individually. But I do get runoff every watering. I would guess 1-2L run off from all plants each watering.

Is the plant in question bigger or smaller than the rest? Just getting a handle on its water needs.

 

[Zmh]

Is the plant in question bigger or smaller than the rest? Just getting a handle on its water needs.

The two in the back are bigger and got way bigger Buds, but they are more sativa dom strains

The strain with problems is purple punch and is indica dom.

 

[ttystikk]

The two in the back are bigger and got way bigger Buds, but they are more sativa dom strains

The strain with problems is purple punch and is indica dom.

Two issues; one is the size difference, where the small one might be getting flooded and the second issue is that sativas and indicas have substantially different needs in terms of nutrients and conditions. These could be motivated somewhat with warmer temperatures.

What kind of lighting are you using?

 

[twentyeight.threefive]

I'm using T.A/GHE duo coco grow

DualPart® Coco - Terra Aquatica

Uniquely amongst leading brands, T.A. DualPart® Coco doesn’t need additives for success from seed to bloom : other coco specific […]

www.eurohydro.com

I did flush with strait water, but I gave them a normal feed after flush.

First 5 weeks
30ml grow and 60ml bloom in 60L resorvar @ 1,4-1,6EC

After I noticed the def
20ml grow, 40ml bloom and 30ml cal mag @ 1,2 EC

I know it's low, but I thought extra feedings made up for that.

I thought 24C was optimum for mid/late flower? I could easily raise the temps abit

Ratio of grow to bloom is correct according to manufacturer recommendations.

I would stop with the CalMag immediately. Their website say the two bases are already calcium and magnesium rich. Adding more can cause a lockout.

Feeding lower but more often, doesn't supply more nutrients it just provides a more constant supply of lower EC nutrients.

I'm not familiar with your line of nutrients but perhaps just a stronger feed of the base nutrients would suffice.

Also I'd never flush with plain water. I wouldn't worry about runoff pH either.

As far as temperatures go I like my temperatures around 80F with LED. Surface leaf temperature will be lower than ambient air temp because of LED lights.

 

[Zmh]

Two issues; one is the size difference, where the small one might be getting flooded and the second issue is that sativas and indicas have substantially different needs in terms of nutrients and conditions. These could be motivated somewhat with warmer temperatures.

What kind of lighting are you using?

Yeah but I have a pump for the run off, so I don't have to worry about watering to much.
Maybe I'm watering to frequently tho, but according to the research I've done coco is optimal between 90-100% saturation and that's why I water 5 times a day.

Next time I will grow more similar strains, but I wanted both day time and night time weed this round.

The lights I'm using is lumatek Zeus pro compact

LUMATEK | Professional Lighting

Professional Lighting solutions for retail, indoor and large scale horticultural projects.

lumatek-lighting.com

 

[Zmh]

Ratio of grow to bloom is correct according to manufacturer recommendations.

I would stop with the CalMag immediately. Their website say the two bases are already calcium and magnesium rich. Adding more can cause a lockout.

Feeding lower but more often, doesn't supply more nutrients it just provides a more constant supply of lower EC nutrients.

I'm not familiar with your line of nutrients but perhaps just a stronger feed of the base nutrients would suffice.

Also I'd never flush with plain water. I wouldn't worry about runoff pH either.

As far as temperatures go I like my temperatures around 80F with LED. Surface leaf temperature will be lower than ambient air temp because of LED lights.

Yeah Im gonna get my temps up abit. Would it be stupid to bump the EC up to 2 for the next feed? Usually I gradually increase my EC

 

[twentyeight.threefive]

Yeah Im gonna get my temps up abit. Would it be stupid to bump the EC up to 2 for the next feed? Usually I gradually increase my EC

IDK I always do incremental increases like you normally do.

 

[Zmh]

IDK I always do incremental increases like you normally do.

I see, I'll guess I will find out then

I will either have to handwater that plant for the remaining weeks, or just keep it automated and give them a heavier feed in-between.

I guess the plant in front left also could benefit from higher EC feed. Doesn't have any defiency but buds are very small

 

[ttystikk]

Yeah but I have a pump for the run off, so I don't have to worry about watering to much.
Maybe I'm watering to frequently tho, but according to the research I've done coco is optimal between 90-100% saturation and that's why I water 5 times a day.

Next time I will grow more similar strains, but I wanted both day time and night time weed this round.

The lights I'm using is lumatek Zeus pro compact

LUMATEK | Professional Lighting

Professional Lighting solutions for retail, indoor and large scale horticultural projects.

lumatek-lighting.com

Is that LED?

 

[Zmh]

Is that LED?

Yeah 465w LED

 

[ttystikk]

Yeah 465w LED

Because LED light emits much less infrared (that feeling of warmth when you put your hand under the light), I recommend you run your environment about 5 degrees warmer than you might with HPS or CMH style lighting. That will help improve plant metabolism, nutrient uptake, growth and maturation.

Your indica dominant plant might be shorter than your sativas (mine usually were) and so a bit of creative adjustment may be in order. Plants further from the light will get less of it. All of these factors may be playing a role in what you're seeing.

 

[Zmh]

Because LED light emits much less infrared (that feeling of warmth when you put your hand under the light), I recommend you run your environment about 5 degrees warmer than you might with HPS or CMH style lighting. That will help improve plant metabolism, nutrient uptake, growth and maturation.

Your indica dominant plant might be shorter than your sativas (mine usually were) and so a bit of creative adjustment may be in order. Plants further from the light will get less of it. All of these factors may be playing a role in what you're seeing.

Yeah I have both windows in the room open with -10C outside right now cuz I tried to keep the temps down lol. I will aim for 27-28C from now on.

I didn't know what to expect from these as my previous run was some horrible bag seeds.

I already had to give one of the girls in front a lift, didn't get sufficient light the first 5 weeks or so. It was partly shaded from the other plant also. Maybe that's why it has so small buds

 

[treefarmercharlie]

Yeah I have both windows in the room open with -10C outside right now cuz I tried to keep the temps down lol. I will aim for 27-28C from now on.

I didn't know what to expect from these as my previous run was some horrible bag seeds.

I already had to give one of the girls in front a lift, didn't get sufficient light the first 5 weeks or so. It was partly shaded from the other plant also. Maybe that's why it has so small buds

With LED you can get upwards of 88°F (31°C) without any issues. I usually aim for 85°F (29°C).

 

[m4s73r]

This can be a struggle depending on the type/efficany of the light. In my 5x5s i can get humidity under 58% but my heat drops to 78°F. Quite the balancing act.