Sudden droopiness for all the plants. Whaaat's happening?

DWC, 600W MH and for the past 24h also a cooltube. Because of the cooltube I was able to set the light at 10-15 cm (4-6 in) from the tops. When light on I have temp at 26 C (78.8 F), when light's off it's at 14 C (57.2 F). Water temps at up to 19 C (66.2 F). I'm feeding them 450 ppm at 5.9 pH.

Also, I connected the room's only forced air out vent pipe to the cooltube for some extra circulation power, so the room was left with one unforced 16 cm (6.3 in) diameter pvc going straight to the attic for ventilation. Attic is very cold, outside is -14 C (6.8 F).

So, as seen on the pictures, it happened over the few last hours of the previous light's on period.

What's going on, why the shock?

Roots arent getting enough oxygen. If your pump isn't adequate, easy fix, get a better one. If your water is churning lots and you're sure it's aerated enough, then look into beneficial bacteria to keep the water "healthy". You could also go the sterile route with h2o2 but i havent had success with this option.

good luck.

I did change res some 48 hours ago, stuff that went in was much cooler than stuff that came out. But that effect almost two days later, I'm not so sure about that.
But maybe because of the cooltube my air temps dropped and when air temp drops the water also drops, no? Especially when in the room there's 14 C.

Also, with the res change two days ago, I added some hydrogen peroxide just to be sure. I think water should be healthy.
There should be enough of the air bubbles. Maybe not... but then why now all of a sudden the droopiness? It happened blitz.

And there's no slime on the roots.

How high was the light before you added the cooltube?
4-6" is way too close for 600w on small plants, i know you have the temps sorted but i would still back that light off to around 16"



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reddiamond said:

How high was the light before you added the cooltube?
4-6" is way too close for 600w on small plants, i know you have the temps sorted but i would still back that light off to around 16"

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I had it before at about 22 in.
Riight, that graph is quite good. I thank you for that!

So basically by setting the light too close, I gave them too much light, right?
How big they have to be to set the light as close as possible?

I see nute burn on a few of them to much nutes. i agree not enough air go buy an air pump for a 300 gallon fish tank with 4 outputs get 4 t splitters and then you have 8 lines pumping air you might need more air stones.

as for light distance can you put you hand in their and hold where your palnt is then you are good, now you need to move air around so have a fan blow between the light and plants. theri is no need to get closer than the chart shows.

DCobeen said:

I see nute burn on a few of them to much nutes.

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I thought it was lack of food. 48 hours ago they were fed at 280 ppm. Today they are 48 days from seed.
A link to the thread https://www.rollitup.org/dwc-bubbleponics/787045-nute-burn.html

DCobeen said:

i agree not enough air go buy an air pump for a 300 gallon fish tank with 4 outputs get 4 t splitters and then you have 8 lines pumping air you might need more air stones.

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My res has 23 litre (6 gallons) of water in it. Air pump is meant for a 150 litre (40 gallon) fish tank. I have one rather small air stone, should get some more.

DCobeen said:

as for light distance can you put you hand in their and hold where your palnt is then you are good, now you need to move air around so have a fan blow between the light and plants. theri is no need to get closer than the chart shows.

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Well. If I put my hand on the cooltube's glass, it felt cold. Like window glass cold.
So I figured to lower the light significantly. But I'll rise it back to 16'' mark.

Helmut79 said:

I had it before at about 22 in.

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A drop from 22" to 6" almost certainly stressed them and also 1 small air stone is nowhere near enough.
Lift the light back to 16" and as has already been said by DCobeen, get some more air in the res and they should perk back up.

I'm on it. Thanks you!

One more thing...

Now, that my 600W Mh cooltube is set at 40 cm (16 in) from plants, air temperature under the light has dropped to 22.5 C (72.5 F). Do I have a problem or is this fine?

I see a lot of good information here. One thing that I did notice in your posts is that you added h2o2 to your res and the problems showed up after that. How much did you add and what strength was it? I have experienced the same problem before and it was too much h2o2. Plants that small I wouldn't add h2o2. I like to use bennies aqua sheild, great white that kind of stuff.

faller200 said:

I see a lot of good information here. One thing that I did notice in your posts is that you added h2o2 to your res and the problems showed up after that. How much did you add and what strength was it? I have experienced the same problem before and it was too much h2o2. Plants that small I wouldn't add h2o2. I like to use bennies aqua sheild, great white that kind of stuff.

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I added 3 ml 17% h202 per litre of res water. I don't have here bennies aqua sheild, great white available, powerzyme instead maybe?

This definitely looks like a water issue. Stunted growth for sure if these are at 48 days. Also, even if heat isnt an issue with the light being closer, the light density can be too intense for the plants. Although I dont see the signs of it, just thoughts i throw that in there. But really to me it looks like a water issue, your using purified water and adding nutes?

When i first started DWC I tried making as little changes to the water as possible, basically just purified it and followed the foxfarm grow chart, had great results. Although the best way to learn is to do, so dont be discouraged because its not going right. My first DWC grow looked the same.

Wow 48 days old. Any chance we can get a picture of the roots?

I am running 450ppm in week 4 of flower right now...

A lightcycle later, almost 18 h, there are no changes in appearance of my plants. I did rise the light to its proper height, 40 cm (16 in). Hence Im putting my money on the water issue. I am pumping my res for a complete water change as I type this.

I also got a new waterpump, twice the wattage of the current pump. And two 14 cm (5.5 in) ceramic air stones.

nicktater said:

This definitely looks like a water issue. Stunted growth for sure if these are at 48 days. Also, even if heat isnt an issue with the light being closer, the light density can be too intense for the plants. Although I dont see the signs of it, just thoughts i throw that in there. But really to me it looks like a water issue, your using purified water and adding nutes?

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Yes, I use only destilled water that has 0 ppm. Then I add nutes and finally I tweak the pH.

faller200 said:

I see a lot of good information here. One thing that I did notice in your posts is that you added h2o2 to your res and the problems showed up after that. How much did you add and what strength was it? I have experienced the same problem before and it was too much h2o2. Plants that small I wouldn't add h2o2. I like to use bennies aqua sheild, great white that kind of stuff.

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I found Algol. Can I use that instead of peroxide?