Wtf is going on?

[sativaplanet420]

I am starting week 3 of flowering 38 plants in 4" rockwool, hydroton, and co co mat under one 1000 watt hps on light rail. Usually 72 degrees and 50 % humidity
I am using a 4' x 8' table. I have a 6" HO intake fan in my garden and a dehumidifier outside it. I use a 50 gallon reservoir without any lid.

My EC keeps rising. I started week one flowering @ 700 PPM and got Nutrient burn and leaf curl. I monitor everyday with brand new EC/PH Hanna Pro pen. My plants are not taking in a lot of nutrients. My EC continues to rise.

I keep adding water and it's down to 650 ppm on week three!!!

What do I do? Flush? Start raising nutes when my EC drops? Is my h20 evaporating?

Any ideas?

My plants are doing decent, but not perfect. Some fan leaves still curled. A lot of nice little nuggets are starting to grow as well.

 

[2cimdma]

Could be root rot

 

[trouble9039]

check ur system out and maybe even clean it! When was ur last res change? Get A lid for ur res that might even be the problem.

 

[sativaplanet420]

check ur system out and maybe even clean it! When was ur last res change? Get A lid for ur res that might even be the problem.

There is no lid for my res. Last res change was one week 2 days ago. What about covering it with pond liner? It won't be air tight though . . . . .

 

[peach]

If water is evaporating from the system, the concentration of the conductive ions will rise and the EC pen will say so. It could be that you're loosing H2O to the air around the plants quicker than they're eating up the nutrient.

The lid to your tank doesn't need to be 100% airtight, just reduce drafts. The humidity will build up inside it and slow down the rate it's evaporating off. Although, that depends a lot on how hot it is where you are, how big the opening on the tank is, where the tank is and things like drafts over the top of it. If you want the budget option, saran wrap the top closed. Having it closed it also good because it'll slow down the rate bacteria and fungal spores get into the tank, which will slow down the rate your solution gets messed up by competitor forms of life. Mold seems quite happy living on nutrient mix.

A more likely suspect is under your lights. Is your feed system enclosed or open to the air in places? The heat from a 1kW lamp will easily evaporate quite a lot of water, especially if there's a fan around. I've watched liters disappear from my tray over a few hours.

It's also possible your pen is not calibrated properly.

I'm using ionic grow and am running about the same ppm as your pen is reading at a pH of around 5.7 to 5.8.

I don't have a pen and so can't check it, but I measure mine out in a jug from the kitchen as per the guide on the pack. I've not had a single problem with burn and have some nice looking plants.

Maybe try some experiments. Is there a guide on your nutrient pack telling you how much to add to a liter? If so, find some way to measure out 7ml or whatever it says to use per liter on the pack - maybe a 10ml syringe would be a good choice for accuracy - doing it by eye or some other shaky method will fuck up the point of this experiment.

Let it mix for a few hours or a day and test it with your pen. If your pen tells you it's way lower than it should be, then it may be that your pen has been telling you to add way too much to the tank.

For example, Ionic Grow suggests adding 7ml to each 1l of water and that the EC should read 1.5mS. If I made a solution with 7ml in 1l and found my pen was reading 1, I would have a reason to think the pen might be wrong and telling me to add more than I needed. Particularly if I'd made up a big batch using the pen and it'd burnt the leaves.

With nutrient I personally feel it's a more is less thing. Once the leaves burn, those areas are fucked for energy production and I doubt trying to squeeze those last few % in is going to make a groundbreaking difference in yield or growth rate. No pen or measuring jug is 100% accurate, so purposefully aim to be on the low side of measurements rather than pushing it to dead on or slightly above.

If I need to measure out 310ml of nutrient and my jug is graduated every 50, I'll go for 300 - as an example.

 

[sativaplanet420]

It's a huge pain in the ass to cover my res, I just tried. I have a really low profile table so there is only a few inches between the top of my res and the bottom of my table. My res is a 50 gallon Rubbermaid stock tank. I needed a low profile res, the opening is approx 4' x 3'

My res is located directly under my table. My 1000 watt HPS is about 4' - 5' above the res. I am going to calibrate my pen although I don't think that is the problem. It's reading around 500 ppm in my veg room and my veg plants are doing well.

I am using Botanicare's Pureblend Pro. I use a diluted version of their formula, otherwise it would be too strong. I added H20 again today to lower my ppm. I will check again tomorrow and see if the plants are taking in more nutes.

This is a 9 week plant I think. I am at the beginning of week three. . . . . . . .

 

[peach]

Hmmmmmmmmmmmmm

So I guess from what you've said that the table is basically right over the tank. Is the table a solid surface shielding the tank from the light? If it's a series of channels running over it and light is hitting the tank, it'll almost certainly be evaporating a lot of water straight out of it. A fan over the plants will make it worse, particularly if you're also using an extractor on the lamp to keep it cool.

If you have to, go crazy with the saran wrap - foil also works nicely since it blocks light entirely and reflects it back up at the shaded leaves (works good with baby plants). It doesn't have to be pretty for now, you can always resolve it in round two.

Also, if the plants are only 3 weeks old, it could just be that they're not ready for the full on nutrient pounding.

Judging by your name, you seem to be a Sativa fan. From what I understand, Sativas generally don't take heavy nutrients as well as Indicas. They're generally a more chilled out plant in terms of growth, which is entirely the opposite of the high. They take longer, they spread out more, they have more slender and fewer leaves... all requiring patience.

You don't need to go straight to the label strength once the lights go to flowering. It's fine to build it up from 50% to 75% and then 100% over two weeks or so.

 

[sativaplanet420]

I am in the third week of flowering! My plants are approx 6-7 weeks old overall. They are dominant Indicas, some sort of skunk strain. I lost my Hawaiian snow =(
My res is really hard to get to and my table should block most of the light. It's pretty well shaded.

 

[just4kickz]

Reservoir Temp?

 

[sativaplanet420]

Dude I have been thinking about that. My pen read 17.7C in reservoir, air temp read 73F, humidity read 45% I also have 2 small fans and a Hepa air purifier. It's still rising from 1.2 EC 3rd day of week 3.

 

[trouble9039]

I am also using IONIC and have never had A problem..... When I used GH (micro, grow and bloom) I had alot of problems with ph changes and just could not keep my PH in range!

 

[sativaplanet420]

I got it figured out. My EC/PH pen was a little off. I was overfeeding. This strain I'm growing does not take in a lot of nutrients. I recalibrated my pen today, drained out approx 10% of my reservoir and added fresh H20. I checked on it b4 it's last flood of the day and it read 1240 EC now it's reading 1220. So right now I'm at 1.2 and they are happy. I am going to let it fall a little more and raise it to 1.3 and so on. . . . I am a lot happier now =)

 

[peach]

I got it figured out. My EC/PH pen was a little off. I was overfeeding. This strain I'm growing does not take in a lot of nutrients. I recalibrated my pen today, drained out approx 10% of my reservoir and added fresh H20. I checked on it b4 it's last flood of the day and it read 1240 EC now it's reading 1220. So right now I'm at 1.2 and they are happy. I am going to let it fall a little more and raise it to 1.3 and so on. . . . I am a lot happier now =)

Excellent! Glad you sorted it out.

 

[trouble9039]

Good job! Glad to heard it's fixed, I know the freak out feeling all to well.

 

[huntingbob]

what is the ph of your solution?

 

[trouble9039]

My hydro system is running at 5.5 to 5.8 PH. After nutes.

 

[sativaplanet420]

It is doing it still. Fucking weird. I just keep adding water and it disappears. I run my PH between 5.5 - 6.0
My strain was giving to me. I think it was made for outdoors or something. They are happy with a little leaf curl around 600 ppm in week 3 or 9