RDWC outdoor autoflower ph dropping leafs drooping

Darknes01

Well-Known Member
Hey everyone,
I setup a 12 site RDWC outside and have some auto's going in there. This is a test to see how they will do in the winter months(moved the seedlings to the grow site on Nov 29th 2019). Everything was going great until i did a res change on 1-6-2020 and added GH 520ml micro / 1040ml bloom & 65ml calmag. Ec was 2.05 and ph 5.3 , waited for 2 days to let things stabilize.
on 1-8 ec was 2.11 and ph dropped to 4.9
to correct the ph i started adding ph up over the course of the day.
5ml pH up added @3:13 @3:27 ph5. 1
5ml pH up added @3:27 @3:52 ph5. 3
10ml pH up added@3:53 @5:01 ph5. 5
10ml pH up added@5:01 @7:02 ph5. 6
10ml pH up added@7:02 @9:18 ph 5.7
10ml pH up added@9:21 @12:47 ph5. 8 ec2.15

next day on 1-9-2020
pH 5.7@10:45am adding 10ml pH up @12:32pm ph5. 8
@10pm ec2.15 ph5. 7

Now today 1-10-2020
Ec 2.15 ph 5.5

I cant keep my ph up no matter what i do and i dont think constantly adding ph up is the right way to go.
they dont have too many roots but whatever there is they are looking white healthy and good.
Im wondering if the calmag being added after the micro and bloom could of caused this ?
should i do another water change and leave out the calmag and see if ph stays stable?

I have spent about 10hrs reading every post on here that i can find regarding ph going down / leafs drooping and narrowed it down to.
1. too much air is being pumped into each bucket and causing co2 to rise
2. i noticed green algae growing under the bucket caps ( now cleaned it and spray painted to block all light going into the bucket)
3. water level too high in bucket?
4. maybe add hydroguard now?

what else should i do to fix this?
oh and water temp is about 55 to 70 daily.
IMG_20200110_143112.jpgIMG_20200110_143247.jpgIMG_20200110_143301.jpg
 

opusmaximus

Well-Known Member
I ran into the same problem, algae was my culprit. I bought some aquarium algae killer. After 12 hours I did a res change of only distilled water. after another 12 I did another res change with nutes. Hope it helps
 

Darknes01

Well-Known Member
I would also use the gro along with it. And ph to 5.8.
thanks for the advice, but whats " gro " u said " i would use the gro along with it" sorry new to this stuff :)
should i start using h2o2 after res change? does it prevent or kill algae ?
 

opusmaximus

Well-Known Member
I only had to do that change once. The nutes you're using sound like General Hydroponics ( it's what I use) usually comes with 3 nutes for the basic pack. Micro/bloom/gro.
 

Darknes01

Well-Known Member
and are those square buckets light proof? i'd much prefer black buckets.
ya they are black buckets , i just sprayed them white to bounce light around a bit.
also i am using the lucas formula which should be 8ml micro and 16ml bloom for the whole cycle( i could be dead wrong here) and i decided to add some calmag to help out. using that formula i get that ec.
 

opusmaximus

Well-Known Member
Are those the plants after 1.5 months? I'll have to look into the Lucas formula. I usually stick to the box which says for 6 weeks 650ml bloom/ 487.5 ml micro. I also use 3ml per gallon of cal mag. Am getting ready to look into the Lucas thing though
 

Darknes01

Well-Known Member
Are those the plants after 1.5 months? I'll have to look into the Lucas formula. I usually stick to the box which says for 6 weeks 650ml bloom/ 487.5 ml micro. I also use 3ml per gallon of cal mag. Am getting ready to look into the Lucas thing though
Yes and do keep in mind they barley get 9 to 10hrs of sunlight per day and still growing like this. Lucas formula is created to just make it easy for people to grow, there are many people loving or hating it. but i like it actually.
 

opusmaximus

Well-Known Member
If you like keep using it. I was just giving some advice. It's a 3 part formula for a reason though. Not saying it doesn't work, I would look into what it might be missing without the other nutes.
 

rkymtnman

Well-Known Member
Am getting ready to look into the Lucas thing though
it's basically using a 1:2 ratio of micro to bloom.

here read this:
 

opusmaximus

Well-Known Member
In march I'll try a side by side comparison with clones from the same plant, Under the same light. Right now my little grow tents are full or I would start em now.
 

Axion42

Well-Known Member
ya they are black buckets , i just sprayed them white to bounce light around a bit.
also i am using the lucas formula which should be 8ml micro and 16ml bloom for the whole cycle( i could be dead wrong here) and i decided to add some calmag to help out. using that formula i get that ec.
Half the Lucas formula to 4mL micro 8mL bloom.
 

Darknes01

Well-Known Member
If you like keep using it. I was just giving some advice. It's a 3 part formula for a reason though. Not saying it doesn't work, I would look into what it might be missing without the other nutes.
i appreciate the help. I didnt mean to come out rude. I did try the 3 part and then swapped to lucas and it was pretty much the same results so i stuck with the lucas formula. There are so many different nuts out there and so many different ways of doing it that its hard to say one is better then the other.
 

Darknes01

Well-Known Member
Half the Lucas formula to 4mL micro 8mL bloom.
thats a good idea. i just started another grow in a tent and forgot to do 4/8 , i wonder if it actually hurts them being full dose (8 and 16) . im going to do a water change tomorrow and for my outside grow i will do a 4/8 and see how they respond. but as far as the lucas formula goes, its said to do 8/16 from start to finish and only use half dose or lower dose if your lights are 400 to 600watts i think.
 
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