Humidity

Hey fellas! This is my third grow, and like any good grower I'm trying to correct some things I've been doing wrong. The biggest issue I think for me is that my humidity is SUPER LOW probably around 10%. I'm growing in a 3x2x5 grow tent, with a 400 watt mh, and an 8 inch inline fan. My problem is that when I leave the inline fan on constantly, the humidity gets bone dry. So what I'm going to be doing is timing the fan to only turn on for 15 minutes every 30 minutes. My question being has anyone ever done anything like this? I have a smaller fan inside blowing just on the light to keep it from getting too hot, and my only real concern is whether or not the 400 watt will turn the room into a 500 degree oven.

What is the outside temperature and ambient indoor temp? A 400 watt HID bulb will produce some heat, but I guess since you're growing in a small tent it could get hotter faster. An 8 inch inline seems like over-kill, are you using a controller for that fan?

I have a 6" inline cooling 2 x 600 watt lamps with air cooled reflectors. With this fan on the low setting and both lamps on, the temperature in my tent doesn't usually break 77 under the canopy (with cold temperatures outside).

10% is really too low. I imagine you are getting some crispy tips.

Whats the humidity outside the grow room you are drawing air from? What's the RH ranging outdooors now for you?

by a fan speed controller from harbor freight and turn the fan down...

booms111 said:

by a fan speed controller from harbor freight and turn the fan down...

Click to expand...

Or, if cash is an issue, a simple dimmer switch can be used as a budget fan speed controller,
But this guys correct
You NEED to tone down the fan speed.

At minimum you need to slow down the fan speed, but you also want to keep the temp within the correct range. I'd like to recommend that you use a humidifier or leave open water in the room (bucket, towel, etc.) The problem with this is that you dont want there to be high RH in the dark cycle, so the fan still needs to be on. It is just the fact that the air is extremely dry right now, so a lot of times the fresh air from an intake is dry to begin with.

Try drawing in air within the room that the tent is in, in their you can try to increase the humidity, and that will in turn keep the tent more humid. It is tough right now with this weather, so I would just try to keep extra water in the tent for evaporation