When to start exhaust fan?

Of the 5 seeds I purchased and one germinated. I planted it in a solo cup
and have it in a 2’ x 4’ x 6’7" tent. It is under two 300 watt LED lamps 26"
above the plant.
My question is when should I turn on the exhaust fan?
Right now the seedling is about 1/2". Should the exhaust fan be run
during the entire stage of the plant? (i.e., from seedling through flowering).
I have an Appolo fan the rates at 390 CFM with a 400 CFM filter.
I will add the other seeds/seedlings as they germinate.

@els011 I would just put a small fan in there not directly on it but some air flowing to move it around st strengthen up :wink: just watch your stretch it will race to the light


I have my three gold leaf spouts 6" away from my 45W/150eq LED lamp. It doesn’t put off much heat, and that close they stay nice and short as a result. As a seedling, running two lamps is overkill, you can save a buck or two by just running one for now. Recently, with 6 seedlings, I did not outgrow the 45W until about week 3 from the time the seed popped up.

There are some nice cheap temp/humidity gauges on Amazon that can be used to monitor highs and lows. At this stage, I doubt those LEDs are driving temps much higher than low 80s (mines about 75deg F),so you are probably good for now.

I don’t have the exhaust going in my seedling tent - at that small they aren’t consuming a lot of CO2 and there’s no need to keep a really fresh air supply.

I should follow @Hogmasters advice, too, and get a small fan in there to build up thier stem strength a bit.

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I am using only one of the 300 watt lamps at this time. I have a small fan to move air. I will get a small lamp to use a 45-watt LED for a short time until the seedlings turn into plants. I would think that would be when they are ready to leave the solo cups. I have a humidity/temperature gauge. I just checked and the temperature is 74* F and the humidity is 47% (N. CA).
Thank you everyone! This is fun!

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45W LED Grow Light, UNIFUN New… https://www.amazon.com/dp/B01F53LP46?ref=yo_pop_ma_swf

I have this.

Now I have one too! (Or ast least I will sometime between next Monday and Thursday). Thank you!