COCO COIR My first grow in 4x4 AC Infinity grow tent, EVO6 - Coco/Perlite - GG#4 & Black Widow

[Wheels1974]

It's hard to say how often MJ plants should be watered because each plant is different and the requirements of various grow mediums is different. Growing in coco, when transplanting sprouts I like to saturate the medium and then go from there. When I say saturate I mean that. Get the medium wet. If that takes 3 quarts or 3 gallons, whatever it is, that's what I do. I want to see runoff in the pot tray/riser. With saturated grow medium at that stage of growth it usually takes about 2-4 days for the pots to dry out enough to water again. As the plants grow of course the frequency of watering will increase. Some say to water with a runoff of about 10%. I like to water until I can see the runoff dripping into the pan and then stop. Try it with your GG1. Give it a gallon and see what you get for runoff. It won't hurt your plant. As your plants grow you will need to feed them more often but you most likely won't be able to put them on a set feed schedule with a set amount of water for each time they are watered. The two factors that will affect how often you water your plants the most are temperature and humidity.

@golfnrl

Your information is extremely appreciated, mate. What you’ve written and the way you’ve explained it is all I’ll need to give it a try.

I think my gut feeling was right, I strongly believe I’ve been underwatering them. I just checked them now but didn't open the tent and they all look awesome. Even GG1, after that 2L feed, has perfect looking leaves. I couldn't get any great shots as I didn't open the tent.

On her next feed, I’m going to follow exactly what you suggested and continue feeding her until I see the first signs of runoff from the bottom of the pot. I’ll then test the EC and pH of the runoff, record the results, and get back to you with what I find. On Thursday I raised her feed from (1.1 EC) to (1.3 EC) and gave her that 2 litres.

Would you suggest keep her 2nd feed the same as her previous week with an EC of 1.3 or increase it to 1.4 or more?

I also need to start defoliation but bloody hell thats quite intimidating, I know I'll start from the lowet part of the tree which is getting quite crazy.

Thanks again, mate. I really appreciate you taking the time to explain it all.

 

[growingisfun]

Looking good!

 

[golfnrl]

Would you suggest keep her 2nd feed the same as her previous week with an EC of 1.3 or increase it to 1.4 or more?

I'm happy to try and help. I'd keep the EC the same for the 2nd feed and keep watching the plant. Raise it slowly until you reach your target EC. I like 1.7 max for veg. A little higher for bloom but each cultivar is different. If you start to see burnt tips, back off the strength of your nutrient solution.

And don't stress too much about defoliating. I'm not the best at it but I haven't killed any plants doing it either. You'll be fine. Don't be shy about taking foliage from the lower parts of your plant, especially those areas that don't get enough light. GWE has lots of really good tutorials about defoliation.

 

[Wheels1974]

I'm happy to try and help. I'd keep the EC the same for the 2nd feed and keep watching the plant. Raise it slowly until you reach your target EC. I like 1.7 max for veg. A little higher for bloom but each cultivar is different. If you start to see burnt tips, back off the strength of your nutrient solution.

And don't stress too much about defoliating. I'm not the best at it but I haven't killed any plants doing it either. You'll be fine. Don't be shy about taking foliage from the lower parts of your plant, especially those areas that don't get enough light. GWE has lots of really good tutorials about defoliation.

@golfred
Plants are all looking amazing, BW2 & GG1 are looking awesome.

I did what you sugested Re: GG1 and after 2L of feed with an EC of 1.3 & pH of 5.8 I had enough runoff which freaked me out EC was as high as my EC would read at 3.8 and pH of 7.3 so I continued watering to 4.5L and got at least 400ml runnoff and nothing changed so I stopped watering. Other then that all plants are looking amazing.

What to do regarding EC & pH runoff?

 

[Allotrope1000]

I sorta follow @golfnrl 's watering program.In 50/50 coco/perlite, 7 gallon fabric pots. (No autopots.)
- water daily until saucer under riser gets a couples ounces of runoff.
- lift pots to judge weight, which indicates those needing extra water.
- keep doing until harvest, of course switching veg to flower nutrients then flush.
It is virtually impossible to overwater in coco.

 

[Wheels1974]

I sorta follow @golfnrl 's watering program.In 50/50 coco/perlite, 7 gallon fabric pots. (No autopots.)
- water daily until saucer under riser gets a couples ounces of runoff.
- lift pots to judge weight, which indicates those needing extra water.
- keep doing until harvest, of course switching veg to flower nutrients then flush.
It is virtually impossible to overwater in coco.

Even though the plants looked amazing last night prior to feeding and GG1 was looking the best I've ever seen her.
Does my EC & pH runoff concern you because they are so high at EC 3.8 and pH 7.3 after multiple attempts?

When I feed next do I continue feeding them the same EC and pH or do I drop the EC when I feed next and if so how low to drop EC and im assuming pH remains the same at 5.8 during all feeds?

 

[golfnrl]

Even though the plants looked amazing last night prior to feeding and GG1 was looking the best I've ever seen her.
Does my EC & pH runoff concern you because they are so high at EC 3.8 and pH 7.3 after multiple attempts?

When I feed next do I continue feeding them the same EC and pH or do I drop the EC when I feed next and if so how low to drop EC and im assuming pH remains the same at 5.8 during all feeds?

The most likely reason the runoff EC/PH is high is because the built up salts from your nutrient solution are not thoroughly washed out. The flush needs more volume. Increase it to at least 2x (Preferably 3x) the volume of your grow pot. I don't think at this point I would do it again though unless the plant was dying. You are a long way from that. When watering your plants with 10-20% runoff each time you are in affect flushing out the unused salts. Just for future reference when your runoff EC is within .2 to .4 of your starting solution your plants are properly taking up the nutrients.

Keep the EC the same but vary the PH. When you increase the EC, going up more than .2-.3 points runs the risk of burning the plants. When you want to increase it to your target number do it incrementally every other time you water. 1.3 EC is at the low end for the veg state. Low does not mean your plants are starving. MJ takes up nutrients at different PH levels. Check out the hydro chart. Coco is considered hydro. When you top water it's OK to use the entire PH range for coco, varying it each time, or every other time.

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[Wheels1974]

@golfnrn Thanks for that information and the nutrition charts relating to pH, that was a great read.

If I'm not mistaken, when flushing, it states:

"You need to remove the buildup. A common way to remove salt buildup is to flush the plant with about 3x as much plain, pH’ed water as normal. Then go back to your normal feeding schedule (make sure you check the runoff pH again afterward, to make sure that your flush worked)."

Every time I've flushed so far, I've actually given them the same EC and pH as their normal feed required. For example, on Friday, GG1 received 4 litres of feed at an EC of 1.3 and pH of 5.8.

Apart from the first week or so, I've never given the plants just pH adjusted water. So I'm just trying to understand the correct way to flush.

1. When flushing, should I use plain pH-adjusted water with no nutrients, rather than my normal feed?

2. My tap water has no measurable EC. Is it okay to use this water, adjusted to pH 5.8, for the flush?

3. Or should I raise the EC slightly first, to around 0.2–0.4, and then adjust the pH to 5.8?

4. Once the flush is finished, should I immediately return to my normal nutrient feed, or should I leave the plain pH water as is for that feed?

I've been using nutrients every time I've watered apart from the first week or so, so I just want to make sure I'm understanding this correctly, especially now that my runoff EC has been off the charts and I tested my EC in 2.77 and it is showing 2.6 solid slightly off but im purchasing the cleaning kit and will give it a clean before using it again tomorrow.

I also topped GG1 and BW3 today. I had a mate have a go at some LST, although neither of us really knows what we're doing yet . I'll also need to start looking at defoliation ASAP and on that topic, is it ok to cut those huge fan leaves that are as big as your hand?

Apart from that, the plants are looking as healthy as I've ever seen them, so thanks to you all! GG1 is no longer wilting now that I'm aware I was underwatering these girls.
Thanks again everyone, I really appreciate all the helpful information you guys pour out each time I post, it really means a lot to me.

 

[golfnrl]

1. When flushing, should I use plain pH-adjusted water with no nutrients, rather than my normal feed?

2. My tap water has no measurable EC. Is it okay to use this water, adjusted to pH 5.8, for the flush?

3. Or should I raise the EC slightly first, to around 0.2–0.4, and then adjust the pH to 5.8?

4. Once the flush is finished, should I immediately return to my normal nutrient feed, or should I leave the plain pH water as is for that feed?

1. Yes.
2. Adjust your tap water to .4 EC then adjust the PH. I use 6.0 to flush
3. See above
4. After the flush let the pot drain. Then immediately water it again with a slightly milder nutrient solution, let that drain, check that runoff and you should be good to go.

It's OK to use nutrients every time you water. There just needs to be enough runoff.

Are those Bud Trainer Bud Clips that I see in there? I really like their products. Looks like you have your BW2 tied down and your GG1 looks good as well.

Yep, read up on defoliation at GWE. Others are better at defoliation than I am and may have something to add. The fan leaves can and should be removed if they are blocking bud sites. I like to leave as many as possible otherwise because they contain stored energy for later use. Most of the time I leave them alone until I defole about three weeks after the flip. Sometimes I do that just to see how big they will get.

 

[Wheels1974]

@golfnrl
Awesome feedback as always I'll try that in the next week when shes due for a feed. When you say "Then immediately water it again with a slightly milder nutrient solution, let that drain, check that runoff and you should be good to go."

If she was due for a feed with an EC of 1.3 would you make your slightly milder mix to 1.00 or lower?

Lastly I got my "Blulab conductivity probe care kit" gave it a bit of a scrub and measured EC in 2.77 and it was flashing between 2.6 to 2.8 so the cleaning of the EC definitely worked.

 

[golfnrl]

If she was due for a feed with an EC of 1.3 would you make your slightly milder mix to 1.00 or lower?

1.0 will work just fine. Glad your BlueLab equipment arrived.

 

[Wheels1974]

1.0 will work just fine. Glad your BlueLab equipment arrived.

Thanks mate and to bring my EC up to 0.4 will just CalMag be fine without Canna A&B for the flush?

 

[golfnrl]

Thanks mate and to bring my EC up to 0.4 will just CalMag be fine without Canna A&B for the flush?

yes and adjust PH.

 

[Chipmunk]

@golfnrl hit it spot it. BTW, Wheels, nice seedlings for a first time grow.

You old growers know this, but I thought I would toss out the below, sort of plant chemistry 101 for those interested.
"Cation exchange capacity" is a normal function when using coco coir. A cation is a positive ion that the coco absorbs. Usually magnesium (Mg2+) or calcium (Ca2+).
Coconut husks are broken down by soaking in seawater or brine. During this process sodium (Na+) and potassium (K+) cations are absorbed. The cellulose, hemicellulose and lignin components of coco have negatively charged sites, carboxyl (CO2-) and hydroxl (OH-). The coco releases the Na+ and K+ into the grow medium preferring to "suck out" the Mg2+ and Ca2+. Magnesium is the essential, central element of the plant's chlorophyll molecules. You want plenty of magnesium for your plants to grow and be healthy, which is ensured by adding a calmag supplement. Reused coco is well "buffered" and should not need lots of calmag.
Look also at GWE's pH/element absorption table. Correct pH range is essential for yours plants' ability to use the necessary nutrients. Also, pH is a logrithmic scale. pH 7.0 is 10 times more alkaline than pH 6.0.

My tap water is super hard and often pH 8.0+ so I do not measure EC. I do cheat when adjusting the pH, though.
I use nitric acid (HNO3). The H+ cation lowers the pH and the NO3- anion adds additional nitogen. DON'T run out and buy some, though. It is VERY CORROSIVE. A drop will burn a hole in your clothing and stain your skin yellow. Regular grow store pH down works just fine.

Spot on with your chemistry!

 

[Wheels1974]

@golfnrl thanks so much mate.
I flushed BW3 on Monday or two days ago, and this time I got my flushing solution down to an EC of 0.4 with a pH of 5.8 before commencing.

The first runoff appeared after about 2 litres, and the EC was still 3.8 with a pH of 7.4. I continued flushing, but even after 5 litres there was absolutely no change.
Thankfully, after 10 litres, I finally saw the EC start to decline, dropping from 3.8 to 3.2, while the pH remained at 7.4

As soon as I saw that EC finally move, I felt like I'd won a bloody major prize, no kidding!
I continued flushing, and after 18 litres in total the EC had dropped to 1.1 with the pH at 7.3

I was quite satisfied with the EC reduction at 1.1, so we stopped flushing and gave BW3 a normal 2 litre feed at EC 1.0 and pH 5.8.

At least now I understand exactly where I was going wrong. I should have asked earlier whether the flushing solution itself needed to be at extremely low EC level.

Previously, I was flushing with nutrient solution at the same EC I had been feeding the plants, and that feed EC was increasing as the weeks went on. So I was effectively trying to flush accumulated salts while continuing to add nutrients at the same time.
That was a really important lesson for me.

The biggest thing for me was actually seeing the EC finally start dropping. I had been up until 6am the first time I dealt with this just a few weeks ago, and the second attempt was another very long night, finishing around 5am. Then I was up again until 6am this time.

Yesterday I flushed BW2 & BW1
BW1 only needed 10 litres of EC 0.4 & pH of 5.8 before getting runoff that had an EC of 1.1, and BW1 took 14 litres before her runoff EC reached an EC of 1.00, which took around 5 hours total.
I then gave both plants a 2L feed with BW2 getting an EC of 1.2 & BW1 an EC of 1.1 - After flushing is this the correct method, to feed them again with the same nutrient levels they were getting on there previous feed OR should I drop the EC ever so slightly compared to their previou feed?
At lease now I know I'm giving them the correct pH with every feed NO MORE pH strips.

Just finished flushing GG1 tonight, she took 12 litres and got her EC down from 3.8 to 1.2 then gave her a 2 litre feed with an EC of 1.1

I think I'll flush GG2 also, who is the runt of the tent, despite the probability of me throwing her out is almost a certainty I think It'll be a great test to see if she improves dramatically of not.

It has been an exhausting few days, but well worth the effort. Seeing the EC finally come down to the right levels and understanding what was actually happening has made all the effort worthwhile and again thanks so much for all your ongoing comments that have already taught me so much.

 

[golfnrl]

After flushing is this the correct method, to feed them again with the same nutrient levels they were getting on there previous feed OR should I drop the EC ever so slightly compared to their previou feed?


I think I'll flush GG2 also, who is the runt of the tent, despite the probability of me throwing her out is almost a certainty I think It'll be a great test to see if she improves dramatically of not.

It has been an exhausting few days, but well worth the effort. Seeing the EC finally come down to the right levels and understanding what was actually happening has made all the effort worthwhile and again thanks so much for all your ongoing comments that have already taught me so much.

Make a milder nutrient solution by lowering the EC by two points.

I'm glad to see you are gaining confidence. Your flush could have continued until the runoff EC was .4. 18 L = 4.75 gallons, correct? Flush with 45 L through your 5 gallon pots. And yes, you are correct, the flush solution should be water only or water amended with cal/mag either way with a starting EC of .4 and at the proper PH.

If you have a plant to experiment with, I.E. 'the runt of the tent' flush her with 45 L of water as described above. Don't check the EC or PH of the runoff until you have about 10 - 15 L of flush left to pour through the pot. My bet is your EC at that point will be nearly what you are starting with and that is the goal. If it's not, continue until the entire 45 L has been ran through your pot and then check the EC again. We want to wash out all of the old solution that has built up in the coco. After, water in a milder nutrient solution. I'd bet she recovers. and even if she doesn't keep trying, it's worth the experience.