Completed First time growing ever (Hydro) problem diagnosis with plant?

[Sleeper143]

Hey guys, i have one other question i want to ask. And i cant believe i never thought of this one as a possible cause of sick plant.

My small grow box is 0.75 x 0.75 x 100 cm in size, so its very small.. i have a pretty big carbon filter and fan.. and there is major negative pressure in the tent itself. i do not have an active intake fan, but i do have a filtered duct leading to the outside...which should bring in some fresh cold air, i have a monkey fan blowing air within the tent, and the massive carbon filter throwing air out.. and its creating negative pressure... now.... will this negative pressure deprive the plant of Co2?

thanks,

No, it’s still getting a fresh supply of air. Although you have negative pressure, your tent isn’t collapsing because there’s still air getting in. Negative pressure isn’t a bad thing, at least you know air is getting taken out and new air going in.

 

[x00m]

Well the all sides of the tent are sucked in as far as it can get sucked it. And my temperatures inside the tent can drop to about 11C (51.8F) or lower at night, and in the day it stays around 14c - 20c (57.2F - 68F) depending on the day. The cold temperatures also affects the DWC water temps. This will most likely have a negative effect, so i started using an electric heater to raise the temps to 22C (71.6F). Hope this will work.

 

[Mañ'O'Green]

Well the all sides of the tent are sucked in as far as it can get sucked it. And my temperatures inside the tent can drop to about 11C (51.8F) or lower at night, and in the day it stays around 14c - 20c (57.2F - 68F) depending on the day. The cold temperatures also affects the DWC water temps. This will most likely have a negative effect, so i started using an electric heater to raise the temps to 22C (71.6F). Hope this will work.

Your plant will stop growing at those low temperatures you should be shooting for 68°F night and 78°F Day. 68°F is perfect for the reservoir.

 

[x00m]

So today, i have corrected the water temps with an aquarium water heater a submersible one of course. and ive also corrected the tent air temp with a fan heater set to a thermostat to 72.5F. itl switch off at that temp and wait for it to drop to 68F before switching back on.

here is a picture i just took of the plant.. the lower leaves are... getting worse. The top leaves are looking fine, it is growing very slowly... but im hoping with the temps all corrected. it will speed up. I still dont know about those brown marks on the leaves, im feeding it with Dutch Pro grow Soft water and ive the PPM at 150. Is it too low? too high? also, the lights are now on VEG only.

 

[Mañ'O'Green]

So today, i have corrected the water temps with an aquarium water heater a submersible one of course. and ive also corrected the tent air temp with a fan heater set to a thermostat to 72.5F. itl switch off at that temp and wait for it to drop to 68F before switching back on.

here is a picture i just took of the plant.. the lower leaves are... getting worse. The top leaves are looking fine, it is growing very slowly... but im hoping with the temps all corrected. it will speed up. I still dont know about those brown marks on the leaves, im feeding it with Dutch Pro grow Soft water and ive the PPM at 150. Is it too low? too high? also, the lights are now on VEG only.

View attachment 1201692

Not counting your starting water you should be ~400PPM of nutrients.

Ps she looks much better already .

 

[x00m]

my starting water ppm is 40ppm. so i should feed seedlings 440ppm? that wouldnt shock them? considering its autoflowers? sorry im really new to this, any more clarification on that would be great help.

 

[Mañ'O'Green]

I wish they did their chart in imperial numbers?


Don't worry about being Autos or Photos we will adjust to the plant and not "rules of thumb" Week 2 of veg shows EC 2.0 or max 350ml per 100 liters EC 2.0 = 1000PPM Hanna (most common scale)

My rule of thumb for autos is to start feeding at 50% of the chart in this case that would be 500PPM. I feel this plant is not quite ready for that much but 400 PPM (440 PPM total) should be fine Then every week increase by 10% until you get a little bit of tip burn then back off 10%. Now you are feeding the plant what it wants and not just some chart number.

It is paramount that you keep the nutrients in balance. If you are using A&B at 70% you should be using explode at 70% (when it is on the schedule).

 

[x00m]

Okay thank you for this! I will adjust the nutrients accordingly

 

[Daipot]

Hey guys, i have one other question i want to ask. And i cant believe i never thought of this one as a possible cause of sick plant.

My small grow box is 0.75 x 0.75 x 100 cm in size, so its very small.. i have a pretty big carbon filter and fan.. and there is major negative pressure in the tent itself. i do not have an active intake fan, but i do have a filtered duct leading to the outside...which should bring in some fresh cold air, i have a monkey fan blowing air within the tent, and the massive carbon filter throwing air out.. and its creating negative pressure... now.... will this negative pressure deprive the plant of Co2?

thanks,

the negative pressure is just testament to the exhaust working properly. What size fan is it? Be weary of the temp inside the tent going to low. This is a major possibility considering you have air blowing out and air coming in, this too is more possible as led lights don’t really give off much heat.
As for the plant itself, I’ve never grown dwc but I’ve done many, many grows and I’m currently trying to master NFT, but looking at the plant I’d suggest to start again mate. I know it’s not what you want to hear on your first grow and it sucks but trust me, there nothing worse then ploughing time and energy costs into a grow just for it fail in its later stages. This is something that’s been all to familiar with me lately while trying to learn NFT.

 

[derek420colorado]

She is back on the rebound. How are the roots looking? Are the teaching to the rest our yet? Can you take a picture of the roots/res. (Also for anyone who knows me, or has been here a long time know what question I am going to ask next lol) how much air to you have being pumped into your res? What I mean is how big is your air pump? Having a lot of air will be important due to the time that has been lost dialing it it(not to worry she will end up being huge and frosty)

I have a theory and tek that has some very good support around these parts.its the max O2 tek. I won’t bore you with a bunch of scenceiy stuff but basically more air equals big plants.I love people growin in DWC, I did it for over ten years exclusively. If you need anything don’t hesitate to dm or tag me.