Last Few Weeks Of Flowering; More Light Or Cooler Temps

[DannyO]

I have 7 different strains at day 47 of flower. The earliest projected flower time of the strains is 49-56 days and the latest is day 60-70 days. I have been running CO2 and keeping the temps at 83 degrees. I have heard that I should get rid of the CO2 now and lower temps and humidity so I turned my AC down to 75 degrees only to find out that it cannot get the temp that low with my HPS at 1000w (the coolest it will get is 81/82 degrees). If I turn the light to 75% I can get the temps down to 76.

Is it better to have less light but cooler temps or keeping the light at 1000w and having temps stay around 80 degrees while I wait for buds to ripen?

 

[Polar510]

Is that clip fan tbe only fan in the tent?Nice Colas!

 

[DannyO]

Is that clip fan tbe only fan in the tent?Nice Colas!

That fan is actually on a post from the ground at max height and then on top of a flower pot to get it above the canopy. I also have two clip on fans routing air under from left to right and then blowing up to the post fan on the right side floor. The clip fans are small and dont push a ton of air but that one in the pic moves quite a bit of air. I attached a pic from a few weeks ago where you can see the full post fan and the one on the left; the one on the right floor is the same size as the one on the left(the one on the left now points straight under the plants but in the pic was blowing up).

Thanks!

 

[Polar510]

I wouldnt lower the wattage when the plants are finishing up. It just seems like a bad thing to do IMO I could be wrong..maybe some do.
It seems like the light hood itself might need better air extraction, what are you using to vent the hood? And where are you venting the air to?
I have never ran a closed garden but have a modest backround in Hvac.

 

[DannyO]

I wouldnt lower the wattage when the plants are finishing up. It just seems like a bad thing to do IMO I could be wrong..maybe some do.
It seems like the light hood itself might need better air extraction, what are you using to vent the hood? And where are you venting the air to?
I have never ran a closed garden but have a modest backround in Hvac.

Thanks for the replys.
I have a 720cfm fan sucking through a 8" carbon filter and blowing through the light, then routing up near the basement ceiling where another 420cfm fan pulls it through a 15 foot section of 6" duct and out my dryer vent. The carbon filter is pulling air from the basement which is 80-85 degrees right now because my AC is exhausting right into the basement. I converted a window unit to blow air through 6" duct but I left the external part of the AC open to the basement air. Once this harvest is done I am going to convert the other side of the AC so the ac exhaust will blow through the light and then outside and get the basement temps back down to 75 (I am hoping I dont need ac at all once summer is over).

I definitely dont like the idea of turning the light down now but i also dont want to burn off the terpenes and/or cause any heat stress. Im just not sure what is better. This is my first time and so far I have done ok and dont want to screw anything up at the home stretch.

 

[Polar510]

The exhaust air is usually really warm coming off the AC and damp. Venting an AC in your basement will create a breeding ground for mold with the heat and humidity levels. Its also not a good option for venting the light. Bring in cooler temps to vent the light. Also vent your AC outside at all times. That should lower Your temps substantially.
Reduce as much ducting as You can.

 

[Polar510]

The idea and concept that works for Me is to take room temp or close to it and vent the light and get it the hell outta there asap..keeps the temps in the upper to mid 70's.
But Your so close to harvest You might want to work out all that on the next run. Unless You think the plant are really stressed.

 

[DannyO]

So, I am in a basement with no windows so my only option is to go out the dryer vent. I currently have the air pulling from near the basement floor and across the light and directly outside. If I want to vent the AC exhaust, I will need to vent it through the same outside vent as the light and the only way I can think to do this is to blow it through the light( I do understand it would be ideal to blow cooler air across but I dont have the option to use a window for a second vent).

As for the AC exhaust and mold in the basement, I have a dehumidifier cranking in the basement and keep the humidity at 40% or below. I also have a dehumidifier in the tent but it barely runs because the AC keeps the tent dry.

I dont really see any heat stress on the plants but I was reading that I should be dropping temp and co2 when I am this close to harvest and was trying to do so. I think right now my options for the last few weeks are either light at 1000w and temps around 80/81 degrees or light at 75% and temps at 76 degrees.

Is it possible to put a Y connector on my duct to vent air from both locations into one duct or will this ruin the suction and/or airflow?

-your vent looks nice and short; I wish I could have that luxury :(

 

[fatawa]

Pull them temps back for trichs

 

[DannyO]

Pull them temps back for trichs

Thanks for the reply,
Even if that means taking the 1000w HPS down to 75%?

 

[Polar510]

I think a wye connecter would be your best bet here. When you vent the ac outside of the basement it will make the ac ALOT more efficient.

 

[DannyO]

ok, thanks for the insight. Once this harvest is done, I will work on re-configuring my venting and AC, while the tent is empty.

 

[Polar510]

Right on bro good luck with the temps! I am on a upper level with no ac in the room so It took me a while to figure out how to get temps manageable in My setup. I had to explore every option and go with multiple setups to get it right.

 

[DannyO]

Right on bro good luck with the temps! I am on a upper level with no ac in the room so It took me a while to figure out how to get temps manageable in My setup. I had to explore every option and go with multiple setups to get it right.

Thanks.

I am still figuring things out as I go but I think it will be easier to manage in the winter so after this harvest, Ill probably not have to worry about AC until next spring. I will def look into the Y connector also.

 

[fatawa]

Thanks for the reply,
Even if that means taking the 1000w HPS down to 75%?

no...nite temps.if it was outside like its supose to b fall brings colder nights,which makes female produce trichs to catch pollin from males to reproduce

 

[DannyO]

no...nite temps.if it was outside like its supose to b fall brings colder nights,which makes female produce trichs to catch pollin from males to reproduce

oh, ok. What would be ideal night temps? I currently have it set to about 69 degrees at night.

What is your opinion on the day temps and light? 81 with light at full power or 76 with light at 75%?

 

[fatawa]

Keep it 100%,81° isnt bad.84° n hotter i wud b tweaking.i pull all the way down to 59° last 2wks

 

[DannyO]

Keep it 100%,81° isnt bad.84° n hotter i wud b tweaking.i pull all the way down to 59° last 2wks

Great news! I didnt like turning the light down. Ill crank it back up today. Am I correct that I shouldn't be boosting CO2 anymore?

 

[fatawa]

I dont but some do. @DemonTrich let him weigh in on this.

 

[Polar510]

Like Fatawa said 81 deg is not that bad.
But Your setup could be alot more effecient saving You $$ on the electric bill as well. An ac should never pull air from the same room its venting in.