VPD chart says I need 75% RH

[OBIWANROLLMEWAN]

I have a 4x4 going with 4 plants in it. It's been a little hot lately and I'm struggling with my Mars Hydro Fc-E3000 LED with Temps at 85. Every vpd chart is telling me I need around 75 RH. I have 3 fans. 2 clip on fans up top pointed at the light for the top airflow. Nice tower oscillating fan sitting in the corner. AC Infinity unit is set up to pull the heat out which drops my RH barely. Got a lovely airflow in there..is this RH ok with the airflow I have ? And are the usual mold problems we see people run into running this RH numbers due to lack of proper airflows?

 

[Alter Jean]

Is the plant in bloom?

 

[SBBCal]

You need to check the leaf temp to make that VPD accurate. Do you have a thermal gun? Usually with led it's about 2-3* cooler than the ambient air temp , but every setup is different. Sounds like you have plenty of airflow, but to really maximize vpd , I'd suggest a thermal temp gun. Then plug in your numbers

VPD Chart

Vapor pressure deficit (VPD) chart & calculator for horticulture in controlled environment. Cannabis, tomatoes, leafy greens, cucumber.

vpdchart.com

 

[V256.420]

85 needs around 60 and you should be fine

 

[Dreminen169]

As long as your airflow is good, you should be ok. Especially if In veg. In flower I will not go about 65%

 

[OBIWANROLLMEWAN]

You guys rock for real. Thank you so much! I will adjust accordingly. I'll drop that RH down a tad bit. And no go on that temp gun but I am for sure going to invest in that next!

 

[OBIWANROLLMEWAN]

Is the plant in bloom?

I am on almost week 4 of veg

 

[OBIWANROLLMEWAN]

Is the plant in bloom?

Shooting for about a 6 week veg overall to fill this 4x4 as much as I can.

 

[Broclee]

I am on my 24 of flower. Ambient sir temp is about 88 leaf temp is about 83 and rh is about 70 I have had no problems day by day I'm dail back rh and temp so that mid flower my rh is around 60 rh. If you are worried about mold add a large with great cfm to keep stagnant air moving

 

[OBIWANROLLMEWAN]

I am on my 24 of flower. Ambient sir temp is about 88 leaf temp is about 83 and rh is about 70 I have had no problems day by day I'm dail back rh and temp so that mid flower my rh is around 60 rh. If you are worried about mold add a large with great cfm to keep stagnant air moving

That is crazy how the leaf temp can be so different. Guess I need to for sure look into getting one of those thermal temp guns that the person above mentioned

 

[SBBCal]

You guys rock for real. Thank you so much! I will adjust accordingly. I'll drop that RH down a tad bit. And no go on that temp gun but I am for sure going to invest in that next!

Like 10-15$ on Amazon. Wouldn't worry too much with rh in veg.