Plant problem

I would like some advise.

-indoor
System NFT/hydroponic
-specific medium - rockwool

-Hydro/NFT system type


-Water source rain water passed through uv anti bactieral filter
-Water pH 5.8
-Age of plant 10 days veg & 1 week flowering
-Type of fertilizer General hydro 3 part (flora gro, flora micro, flora bloom.
EC. 1.4
-watering cycle 15min on 45min off
-Lighting source and distance from plant HPS 600w ajustawings reflector with spreader 30cm from plants
-Temperature 28deg day 18deg night(both day and night if you are running a dark period)
-% Relative humidity 50%
-Lighting schedule 12/12
-Type of ventilation your room has 3000m3 extractor and ventilation fans

some more pics
general yellowing of lower older leaves with some plants with leaves curling down. Upper leaves green
yesterday sprayed with 8/8/6 fertilizer 2 ml per liter
Composition : N 8%, P 8%, K 6%, B 0.002%, Mn 0.05%,
Mo 0.002 %, Zn 0.05 %, Aminoacids 5%

Wow....those look like some sick plants. Somehow they are burning. I don't really understand the rain water and UV filter so I'd start to wonder about your water first off. What's the ec of it? Rain water really isn't as clean as some people like to think and I'm not sure about the bacterial thing so I can't comment on that. id also wonder about enough calcium and magnesium from rain water but again, am not sure.

Until you figure out what's going on I'd stop ALL nutes and I'd go back and recheck and recalibrate your ph meter (or at least check and make sure it's calibrated correctly)
I would put them on ph correct water until you can pinpoint the problem. Rockwool is known for it's ph issues. Maybe the ph of yours is abnormal.

From the pics you've provided it honestly looks like everything is wrong. They look overnuted and nuteburned AND they look like your ph is off. That brings me back to wondering about your water. Have you used it before with success?

Hope you figure it out.

Good luck.

Also I don't use rockwool but aren't you supposed to water it about twice a day or something to avoid overwatering? That's just a guess on my part.

I recalibrated Ph meter it was reading 7.5 when it should have been reading 7.
I was growing with earth and I decided to try nft with rockwool as i've read of amazing yealds with it.
I did one previous grow with rockwool and was advised to keep watering system on 24/7 which I did without problems.
I've since spoken to others and one recomends 12hr on with lights and 12 hr off on the night cycle. the other recomends 15min on 45 min off, throughout the 24hr cycle which is what I have now.

Is it possible to rinse rockwool with H2o2 ( hydrogen peroxide) solution to kill any bacteria? If so how many ml per litre?

I'm going to let Weedhound answer the peroxide question, but I'll tell you a little about rain water.

As water passes through the atmosphere, it picks up all sorts of stuff... some of it not so good. In areas that are 'downwind' from a weather-pattern perspective of a pollution source (industrial area, coal-burning power plant, or even a city), rain will have dissolved Nitric and Sulfuric acid in it. The ratio of N:S compounds is directly correlated to how much of the pollution comes from gasoline burning versus coal burning sources. What looks like a Nitrogen overdose on your plants may very well have something to do with this. Just out of curiosity, what is the pH of the rain water when you first test it?

The second, and arguably even more important problem, with rain water is the complete lack of dissolved MINERALS in it. Surface water (lakes and streams) and groundwater (wells and aquifers) both contain significant levels of dissolved CaCO3, the primary constituent of limestone.

So why is this important? For a couple of reasons. Plants need Calcium to grow properly. It is one of the most important parts of a plant's 'diet'. It is considered a secondary nutrient, but it is so important that if you are growing hydroponically from a source other than fairly hard tapwater, you absolutely MUST add a calcium supplement such as CalMag Plus.

What you have there looks to me like a Calcium deficiency and a Nitrogen overdose. You're going to want to switch your water source away from the rain water, and start using a calcium supplement. The roots look white and healthy, so I would not be overly concerned with peroxide at this point, although you might want to add a beneficial bacteria culture to your nutrient regime. SubCulture is one to look into.

Hope that helps.

Thanks :thumbsup::thumbsup::thumbsup:I was cosidering to add calcium but was not sure if the deficiency was because of lock out of nutes and did not want to make the problem worse. I aslo thought spraying with balanced fertilizer would be enough.but i now see it didnt have any calcium!:( The EC of the nute spray was 1.4 EC maybe it was a bit strong?
With regard to the rain water its Ph is 7.0-7.1 with an ec of 0.10 so not much disolved salts.
In the summer when I run out of rain water i get a truck full of well/ground water EC 0.9
Could also do with some advise on watering frequency
:thumbsup:

I dont use rockwool myself but here is some info on it. Hope it helps..

Hydroponics - Rockwool as growing substrate

listen to Stinky about the rainwater, i've read all that before, but all i could fathom up as a response was "Don't use rainwater, its bad!"

i wanna be smart :clap::detective1:

I don't have much choice, the tap water has an EC of between 8.5 & 13 so its impossible to use that. i could get water delivered by the lorry load but would have to keep it in the tank with the rain water catchment. alot of hydro guys use RO(reverse osmosis)water which also has no calcium etc. So i thought rain water is fairly similar RO water has EC 00 my rainwater EC 0.1. I use Uv sterilization light to permantly alter DNA of bacteria to stop it reproducing. I don't know what else to do.

I'd get yourself an RO system and run your rain water through it......you're already going to need CalMag using the poor rainwater......take the same water and RO it....then use it. You shouldn't need the UV sterilization either but could still use it if you wante too. The trick would be how to feed the rainwater through the system since the ones I've seen are designed to hook up to a pressurized water system to run.

Or go to an RO system for your 8.5 SLUDGE.....but I'd go with as many (is it five?) filtration stages as you possibly can if you use tap water.

I think the mother plants the clones came from were already suffering from lack of ca and mg so from the start things were not ideal. yesterday I sprayed them with a mild solution of calcium ang already today they look healthier. I'm going to follow up with a mild solution of mg in a few days and see how things go. I'll post some more pics then.
I'm going to see how it works out with the additional Ca/Mg and decide weather I realy need to change to RO water.
thank you all for your advice...keep it coming...
Free the smoke for all.....:rastasmoke:

sorry to see so many injured plants man....i feel

however, they are not very big for 11 weeks old (even for clones) and i wonder if this has been a problem from the start or not?

but stop using rain water, theres no real reason why its better than distilled, or possibly even tap water.

I have beenusing rockwool for a long time. First thing you to do is figure out how much you feed you plants per min. 25% of that should be run off. usually start feeding about 1 cup per day once. once roots start to grow out bottom of 4 in. cubes i let them run a little dry mabe 1/2 cup per day to make the root look for water in the 8" cubes for a few days then go back to my normal schedual. once rooted in 8" cubes i increase to about 4 cups once a day. this should leave you with about 25% runoff ( about 1 cup ) After this you need to watch your plsnts. when start to look a little dry or heat stress add another watering about half way through your cycle ( about 2 cups) this should give you about 25% runoff. You may have to mess w/ your timming a little bit to get the proper 25% runoff. Now for checking your runoff. If your runoff is showing higher ppm and lower p.h then you need to decrease your total ppm in your res. and vise versa. One other thing you should flush once a week. I like using hydroguard w/ r.o water. dont forget to p.h balace. help this helps. later

you need to keep your res about 5.5 ph. youl see what i'm talking about when your runoff comes out near 5.8. later

Quote:

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Originally Posted by hybridlove420

sorry to see so many injured plants man....i feel

however, they are not very big for 11 weeks old (even for clones) and i wonder if this has been a problem from the start or not?

but stop using rain water, theres no real reason why its better than distilled, or possibly even tap water.

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hi thanks for concern.
the plants had only 10days veg growth from clones and now one week flowering.
Things are looking better since i gave them some calcium & Magniesium.
They have nearly doubled in size in the last 2 days so i can see some sort of normality returning.
here are two more pics.
I'll post some more pics in a few days

Great. They look MUCH happier now.
If you have a sec, go through and remove all leaves that are dead and dying for 2 reasons:
-Dead leaves sitting around attract pests and fungus yuck
-This will give you a starting point of reference to see if there is any more die-off since you have changed your procedure. If not, that was your issue. If you see any more problems, you still have some tweaking to do.

i'm still trying to work out Ca/mg dosing to add to my generalhydro nutes.
I've read weedhounds hydro nute schedule but 50/50 ratio of CalMag and Pro gro seems alot of CalMag,(I'm Not using CalMag, I'm using canna Ca and canna Mg)
I was thinking about using a dose of 0.5ml per liter of both Ca & Mg plus my regular general hydro nutes. Does that sound about right?
On the bottle it says 1-2ml per liter, but I asume that is the recomended deficiency dose but not quite sure.
When I sprayed the plants with Ca/mg mix I dosed at 1ml per liter of each.

Unfortunately I'm not sure how the Canna and GH ratios would compare; what I'd do is start at a rather low dose of the Ca/Mg additives (so maybe half of what the bottle says to start), watching the low leaves for signs of Ca def (yellow with necrotic light brown blotches) and the middle leaves for Mg def (clearly-defined pale stripes between the veins). Adjust your nutes accordingly if you see this. Be careful not to go too high too fast, especially with the Mg supplement.

I think I added too much Mg. first they started to look better and then worse. big leaves are quite dark and curling down with some lower leaves still yellowing, some of the roots looked with not much root system and off white maybe from nute burn.
2 days ago I dumped the nute solution, sterilized the tank with H2O2 and flushed the plants with a solution of H2o2 ran the system on/off till the folowing morning. The next morning I dumped the res EC.0.6 filled the tank with water EC. 0.1 and ran the system as normal. This morning the plants looked healthier some leaves even have a healthy shine :) I checked EC 0.4 will keep it with same water till tomorrow. If the EC is the same in the morning and depending how the plants look I'll add my General Hydro nutes at 1/4 strength and see how I go from there. This morning I flushed the mother plants with water as they also looked over nuted with leaves curling down. Already they Sprayed all plants and soaked rock wool with water and rizotonic 4ml/L.
did'nt put any pics. embaresed

Next time I add ca or mg I will measure the start water in this case EC. 0.1 and add ca & mg until The EC is between 0.3 & 0.4
which I believe to be the EC of softish tap water. I believe this is much beter than even going by manufactures Nute recomendations even at half doses.

Not too sure if I should add equal parts of Ca & Mg.
I was thinking to add 2 parts Ca to 1 part Mg as i believe generally there is more Ca than Mg in good tap water but would like your input on this.

Thanks in advance

Interestingly.....according to my hydro man.....its VERY hard to OD on CalMag. If your leaves are going all dark and curly that just plain sounds like overnute to me. I sat down the other day and had a fair discussion on the use of CalMag with my hydro guy.....i'll be using it MORE these days instead of less. Just a thought I'm tossing in.....;)

Not quite sure of what it had too much of but the flushing seems to be working:)
In your calmag nute what is the ratio of Ca & Mg?
Does soft tap water generally have more Ca or Mg?

Soft water generally has less of both. The only real way to know exactly what is in your water is to have it tested.

When you see your plants startng to look burned you might just try lowering your e.c. instead of picking one nute or mineral and thinking that caused the problem. Just lower your entire e.c. and see it helps. :)

Another thought and forgive me if this sounds harsh......it seems to me that when you've improvised things its gotten you into trouble. (rainwater etc....) If I were you, I would look at the directions printed on the back of your bottle and stick to them.....although using nutes at the same ratio but less total e.c. usually works best imo.

Think about this: 1. You just paid good money for those nutes. Wouldn't it be wise to use them the correct way?

2. Who wants you to get the best out of their product? The people who made it. So it makes sense that they are going to tell you the best way to use it. (see.....they want you to buy their product again......)

I strongly suggest you try NOT adding your own ideas here and see if that works.

Good luck.

Again....apologies if that sounds harsh but your "improvements" here just aren't working.

Thank for the input but I sorry to disagre but logic tells me otherwise.
The manufactures make nute solutions for both soft & hard water.
By doing this they must find the average disolved salt levels for both soft and hard waters and then make thier formulas to suit the average soft water and hard water.
Therfore I took what I consider to be an average soft water salt level for soft water to be about EC.0.4-0.5
Therefore I took my EC. 0.1 water and added Ca & Mg In equal parts until an EC of 0.4-0.5 is atained.
I have written to canna and GHE on the subject.
We shall see what they have to say.:thumbsup:

My last comment......your first grow.....these folks have been making this stuff for years (and testing, tweaking etc....) Who am I going to believe......logically?

Have a good grow.

If i have to eat my words thats no problem....
But I'm looking forward to hearing from canna & General Hydro