Humidity questions..

Hello,

I have read a few things stating different facts and opinions, I am worried about the humidity in my downstairs room.. same room as sump pump so that may be why ... anyway

Rooms is fluctuating from 67 to 75 between on and off cycle and humidity is about 70 percent, I can get it to about 50 if I open the doors but around 60 to 70 if I leave it sealed up

I do not run co2 and was thinking of doing that to make the most of the high humidity .. the dehumidifier isn't doing much .. I have a fan in each corner so air flow is good and I may try and start venting the flower into the colder veg room hopin that may help ..

Any advice, do you think it'll be ok as is ? The plants are killing it right now and no signs of mildew.. they are packed and that's why I worry

Should I buy another dehumidifier, do you think it's because of water in the sump, should I pop a hole in the wall and vent or invest in co2, using co2 is 60 to 70 where I need to be ? Should I just try and control the temp swing and that will be enough to avoid mildew ? Let me know what you think

Are you venting to outside or in the same room ?

I would be venting to a different room that i think is to cold as it is, only has flouresents in it and being a basement in MI it is pretty cold in winter

The room I'd be venting into humidity is pretty low like 40m sometimes lower and then one room over humidity like a mofo... that's why I was thinking sump pump and heat

To lower humidity you must have air movement the more air movement the lower the humidity. And for flowering should be under 50%