Photoperiod veg time?

Hello there.

I was growing autos for first time and my first grow. I failed so bad. I got 10g per plant (two plants and total 20g) after 9 weeks under 1000w hps. I didn't gave any nutrients first 4 weeks and then i overwatered few times. So they are pretty small. Autoflowers not forgiving any mistakes. So i will go for photoperiods which is you can control many things better than autos.

So i will write what i have now and want to know your opinions about veg time and other things.

Grow Tent: 150x150x200cm (5x5x6.5 feet)
Pots : 6 gallon fabric pots (22 liters)
Strain: 6x Big Bud XXL (photoperiod)
Nutrients: Advanced Nutrients Perfect PH Grow, Micro, Bloom
Light: Philips 1000w HPS
Ballast: 1000w Magnetic Ballast
Cool Tube: Yes
Intake Ventilation: 180 m3 S&P TD-160 Silent Mini
Exhaust: 580 m3 S&P TD-500
Carbon Filter: 665 m3 carbon filter

So that's my setup. Now here is my questions.

1. How long to veg in 6 gal pots with 1000w HPS? I am thinking about 6 weeks of veg + SCROG net. Is that okay?
2. Can i easily hit 0.50 GPW with 6 weeks of veg with only using Advanced Nutrients PH Perfect Grow, Micro, Bloom?
3. I have heat issues. Even with 580 m3 exhaust fan, it's still 30-35C inside grow tent when it's closed (RH is between 30 at day times, 60 at night times). Is that really big issue? It might go higher at summer peak (Jun, July, August).

Thanks.

The biggest thing is going to be the environment. It is way too hot and dry. Do some reading on VPD for cannabis just to learn about the proper environment to help your plants grow. The conditions you described are terrible for young plants that want lots of humidity. The heat is just a little bit too much but the humidity is what's killing you. You would need humidity around 70% to make seedlings happy at those temps. That would be for early veg growth as well. Then it's best to keep it in the 50% range for early flower at least for those temps if not higher. You should look into a humidifier for sure if it's possible. An AC would be great but it's a big expense. A big enough humidifier could get you much more in range and help dial in the tent though. It's possible to grow in very low humidity but much more difficult and the plants grow slower in my opinion. Hope this helps.

Veg with a metal halide as an hps in veg causes stretchy plants and slower growth
My best guess 6 weeks ish

Yeah i did read about importance of RH. I also have 5LT humidifier 380mL/h but it's only making me to catch 30%. But night times it goes up to 60-65%. Heat and RH is really big issue i understand that but that's what i can do now. I will try to fix it anyway. Thanks for your reply.

Any more ideas and answers?

As mentioned, that's WAY too hot and dry for vigorous growth. The leaf's stomata will close to preserve water and then growth stagnates.

So how i can keep temp and humidity high? I really have nice humidifier. 5LT water reservoir and it's releasing 380 mL per hour. When i stop intake, exhaust and 8 inch fan in grow tent (which supposed to cool grow tent but it's not), RH goes up to 99%. But when i plug intake, exhaust and especially big fan in grow tent, a strong wind inside grow tent dries air and it's like there is no humidifier in. I am really looking for solution without buying AC.

I will try to connect intake fan to cool tube. Maybe it's gonna make difference. But it's still damn hot even in April. There will be +15C few weeks at summer peak.

DarkLordMelkor said:

So how i can keep temp and humidity high? I really have nice humidifier. 5LT water reservoir and it's releasing 380 mL per hour. When i stop intake, exhaust and 8 inch fan in grow tent (which supposed to cool grow tent but it's not), RH goes up to 99%. But when i plug intake, exhaust and especially big fan in grow tent, a strong wind inside grow tent dries air and it's like there is no humidifier in. I am really looking for solution without buying AC.

I will try to connect intake fan to cool tube. Maybe it's gonna make difference. But it's still damn hot even in April. There will be +15C few weeks at summer peak.

Click to expand...

What's the RH of the lung room (air outside the tent)? There no need for an intake fan in almost all cases. Passive intake is normally more than enough.

Once plants get larger RH is increase just from them being in there and transpiring. I'd be more worried about being able to manage your RH at lights off in flower.

I've never done HPS lights so I've never had to deal with that kind of heat problems. I know they have special cooling tubes/shrouds for them that allows you to hookup your fan to them and draw air through the light area. That is probably your best bet. You shouldn't have to be exhausting too much air at this point with only needing minimum light for small plants and very little plant biomass to worry about. An 8" fan is overkill for your 5*5 at this point other than the heat issues. Try asking about cooling suggestions in the grow room design area of the forum. Probably get some more experienced HPS help.

In order as far as I can tell:

1. Depends on a few things like strain, nutrients, lights, humidity and temps. If all is good then a guess at 6 weeks is ok but filling out the canopy at the desired height is what you want to judge by if you're scrogging. If you can start LST with a net and fill out the canopy decently by 6 weeks then you're good to go. If you can't wait then it'll be strain dependent. If you absolutely have to flip at 6 weeks then you don't really have a choice if you're giving it everything it needs.

2. Again mostly strain dependent but all those other things come into play as well. You can't force the plant to do more than it's genetics will allow assuming everything else is on point. That's where breeder grow info helps or if nothing else get some intel from growers of that strain if you can that can tell you what to expect, assuming you're doing clones. If it's seed it can be a crap shoot with different phenos.

3. If you can't keep the heat in the low 80's you're going to affect the growth rate as well. High heat can be tolerated if you're feeding CO2 but just high heat itself can cause multiple issues, again depending on strain, nutrients, light etc.

Your best bet is to do your best to create a controllable atmosphere using every tool you can afford. When I started I spent what I had to to get this controllability. Humidifier, De-humidifier, Vent fans etc. I've been through multiple tents, currently run 3 and have AC Inf 6 inch fan/charcoal in each. 2 tents use SF4000 lights, the GGT has a Raging Kush 2 in it. All LED, heat is controllable and the fan system can bring down heat or humidity either way. I occasionally have 1 tent in flower when the others are in veg, that's a humidity issue to deal with. I turn the fans down as low as will keep the temps in range and if necessary use a small humidifier in the veg tent. This keeps more moisture in the tent without sending it out the house or getting it into the flowering tents. If I can't keep the house under temperature control and my setup can't keep everything in the zone then I would shut down in the summer if I can't control it. Thankfully I have central air. In the cold months an open window for air ingress helps keep the temps in control if needed. Even with 3 tents running with those 3 lights I haven't had any controllable parameter get out of control.

1. How long to veg in 6 gal pots with 1000w HPS? I am thinking about 6 weeks of veg + SCROG net. Is that okay?
2. Can i easily hit 0.50 GPW with 6 weeks of veg with only using Advanced Nutrients PH Perfect Grow, Micro, Bloom?
3. I have heat issues. Even with 580 m3 exhaust fan, it's still 30-35C inside grow tent when it's closed (RH is between 30 at day times, 60 at night times). Is that really big issue? It might go higher at summer peak (Jun, July, August).

1. This depends on how far you have from the light, being experienced in blooming with HPS I can say you do not want the plants closer than 2 feet from the light or a ~half meter away from the bulb. Plants can as much as double in size during the stretch period (first 3-4 weeks of bloom) so always take that into consideration.

2. AN GMB works good I started out using it, IMO its expensive and has too much Nitrogen in it. I use CYCO base chart now minus a few things. My brother grew using AN 2 part Coco Connoisseur and has good results and yields.

3. With HPS growing you do not want the air temperature to get above 80 °F or ~27 C ideally... Leaf temperature will usually be 2-3 °F hotter than air temperature with HID lighting such as HPS..

Definitely get your temps under control, you may have to install an air conditioner in the room you're using and have the tent recirculate the cooled air and exhaust the hot air. Definitely way too hot in the tent. Remember terpenes evaporate as low as 77 °F if your temps are 80+ with HPS you're going to lose flavor & smell on your buds an also your plants are going to be mega stressed and you'll be lucky to not get Hermaphrodites and other stress induced problems.

Thanks for all replies. I found a solution: buying AC. It's already hitting to 38C in grow tent. Plugging intake and exhaust fan to cool tube didn't work well. I am going to buy cooler AC which also have humidifier inside with 8LT water and two ice container. I think that will work. So i don't need huge 8 inch fan anymore.

I was thinking to kill my new auto seedlings inside tent now because i didn't like autos but seems like i stressed them a lot with no feeding first 4 weeks, heat and RH issues. Maybe after fixing them, they will grow better.

Right now i have 4 seedlings under 1000w hps. Auto White Widow, Auto God's Glue, Auto Blue Amnesia, Auto Cheese Northern Lights. So i will keep growing them. Probably tomorrow i will have 25C inside grow tent with more than 50% RH. I dont want to loose my faith in this. Yeah this is first grow but it's stressing me more than plants lol.

I will write here tomorrow what's up with grow tent.

Once you get the environment dialed in your stress level will be way more manageable. It's just too hard to grow in a hot dry environment. It can be done, but it's better left to very experienced growers that know how to compensate for it and read the plants very well. Your young plants will do fine with way less than 1000 HPS light. If you can turn it down I would. If not I would raise it up as high as possible. Seedlings have a very low need for ppfd and can be easily burned. Then if you see signs of stretching increase the light or lower it as the case may be until they have gotten to a sufficient size to handle full strength lights. They shouldn't need feeding for weeks depending on the soil you're using. Just water in a suitable ph range for soil.

So it's your second grow?

I wouldn't bother with a SCROG net. I'd top them a few times and then flower them. Just because you see people using nets doesn't mean you have to. So many people just stick a net in their tent because they've seen others do it and then don't use it properly with plants just growing straight up through the net. Keep it simple and get a successful grow under your belt then start doing more stuff.

And don't worry about hitting 0.50 GPW. Just worry about keeping the plants healthy.

DarkLordMelkor said:

Thanks for all replies. I found a solution: buying AC. It's already hitting to 38C in grow tent. Plugging intake and exhaust fan to cool tube didn't work well. I am going to buy cooler AC which also have humidifier inside with 8LT water and two ice container. I think that will work. So i don't need huge 8 inch fan anymore.

I was thinking to kill my new auto seedlings inside tent now because i didn't like autos but seems like i stressed them a lot with no feeding first 4 weeks, heat and RH issues. Maybe after fixing them, they will grow better.

Right now i have 4 seedlings under 1000w hps. Auto White Widow, Auto God's Glue, Auto Blue Amnesia, Auto Cheese Northern Lights. So i will keep growing them. Probably tomorrow i will have 25C inside grow tent with more than 50% RH. I dont want to loose my faith in this. Yeah this is first grow but it's stressing me more than plants lol.

I will write here tomorrow what's up with grow tent.

Click to expand...

Tents have their place but if you're going AC and all that you need to just use the room and not use a tent. I only see tents being realistic for people who are using a 600w light or an LED that isn't putting off lots of heat. 1000w HPS in a tent is not going to be good unless its a huge tent and extra tall.

Look into a stud finder and drill holes for screw hooks in the ceiling for lights, get white paint for the walls and viola my friend you have a grow room instead of a tent in a room. Useful tip on covering windows is using a normal blackout style curtain and then staple something like "Panda Plastic" over the whole window so no light leaks in or out.

xtsho said:

So it's your second grow?

I wouldn't bother with a SCROG net. I'd top them a few times and then flower them. Just because you see people using nets doesn't mean you have to. So many people just stick a net in their tent because they've seen others do it and then don't use it properly with plants just growing straight up through the net. Keep it simple and get a successful grow under your belt then start doing more stuff.

And don't worry about hitting 0.50 GPW. Just worry about keeping the plants healthy.

Click to expand...

Actually first one. Let me show you guys my room.

This is my grow tent (5x5x7):



This is Auto Cheese NL. Problem with that two mature girls, i didn't fed them first 4 weeks because i wasn't have any nutrients. Last 4 weeks, i am feeding them with Advanced Nutrients Grow Micro Bloom. Giving them what's suggested at Advanced Nutrient's Feeding Chart. Auto Cheese NL a bit taller than other girl. I ripped of many fan leaves because they went yellow and dried. Take a closer look.



And here is Auto Blue Amnesia. This one 4 days older than Cheese NL. Also 5-6 cm shorter but more bushy due to genetic. It's same situation with Cheese NL. I didn't fed that one first 4 weeks (or even 5 weeks. I don't remember correctly)



As you can see edge of leaves wilting/curling down due to heat stress (i suppose?).

This one is Auto Pilot XXL. It's at day 15 right now. Is that looks good?



This two girls are new. They are at day 5. Auto White Widows. How about them?


This is my exhaust fan



This is my intake fan, humidifier and extra fan.





And this is what i get with all these equipments. Grow tent is open btw. When i close it, it's gets hotter.

Do you only have only one open intake with the silent mini? You're exhaust fan can only move as much air as can get into the tent. You don't need an intake fan in a small tent. Just use passive intake. Open up and filter the bottom vents. Run some ducting from the intake end of the cool tube to the top of the tent. That way it will pull air from the bottom and out from the top. Heat rises so you want to remove from the top of the tent. That would probably drop your temp inside the tent some unless the room the tent is in is at those temps.

Intake Ventilation: 180 m3 S&P TD-160 Silent Mini
Exhaust: 580 m3 S&P TD-500


I have 3 open filtered vents on the bottom of the tent and no intake fan.

xtsho said:

Do you only have only one open intake with the silent mini? You're exhaust fan can only move as much air as can get into the tent. You don't need an intake fan in a small tent. Just use passive intake. Open up and filter the bottom vents. Run some ducting from the intake end of the cool tube to the top of the tent. That way it will pull air from the bottom and out from the top. Heat rises so you want to remove from the top of the tent. That would probably drop your temp inside the tent some unless the room the tent is in is at those temps.

Intake Ventilation: 180 m3 S&P TD-160 Silent Mini
Exhaust: 580 m3 S&P TD-500


I have 3 open filtered vents on the bottom of the tent and no intake fan.

Click to expand...

So i wanted to plug carbon filter to other open side of cool tube. Anyway, i tried to do what you said but it just made 2C difference.

Can you guys comment on girls?

The thing with autos is they are light feeders. Are you using the schedule for autos or just the feeding schedule by the company? Autos only need about half the recommended feed levels that companies list. So if advanced is saying 4 ml per gallon of grow you should be using 2 ml per gallon. They just don't need to be fed that much. The first couple weeks just water should be fine depending on how hot the soil is your using and then start off at 1/4 strength nutes for a week, then 1/2 strength. If you see signs the plants are hungry during flower you can bump it up a little but that's better than overfeeding them and causing lockouts.

FirstCavApache64 said:

The thing with autos is they are light feeders. Are you using the schedule for autos or just the feeding schedule by the company? Autos only need about half the recommended feed levels that companies list. So if advanced is saying 4 ml per gallon of grow you should be using 2 ml per gallon. They just don't need to be fed that much. The first couple weeks just water should be fine depending on how hot the soil is your using and then start off at 1/4 strength nutes for a week, then 1/2 strength. If you see signs the plants are hungry during flower you can bump it up a little but that's better than overfeeding them and causing lockouts.

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I didn't know that. I am feeding them with my own feeding schedule. And i decide to water them with pushing my finger inside the soil and check if first 2-3 cm fully dry. I don't water them if there is little wetness. So usually i feed them every 4 or 5 days. Also feeding them with company chart. My light schedule is 20/4. Light distance is like 50 cm.

My normal water is 8.3 pH. But nutes that i am using balancing pH of water and reduce it to 6.7~. I know thats still bit high but fine. Using drinkable water, so it's not tap water and not chlorinated.

I know autos are small plants but they always very small to me. Yes, my mature plants i show on pictures are really small but as i said, i didn't fed them for first 4-5 weeks.

Now feeding little seedlings with nutes. Auto Pilot XXL looks bigger to me comparing the mature ones seedling times.

I also overwatered matures with 8.3 pH water few times. Many mistakes i made with these two. But being carefuly with new seedlings.