humidity problem, need help please!

Just bought a new tent setup and after running for two days I have a humidity problem. Its only a 3x3 tent with my 400w for now the 600 is still shipping. I have two plants both in 5gal dwc, when I opened my tent it said 75% humidity with condensation on the walls. How can I fix this without buying some expensive dehumidifier? I'm running a 6" inline fan and carbon filter 440cfm and thought that would pull most of it out. Any help is appreciated, I'm going into week 2 of flower

I have a 5x5 tent and was tring to run a closed system with co2 and failed. I ditched the co2 pulled alot of air out the top bring lots of fresh are in the bottom and im at 40% now. Are you running a cooled reflector? If your tent runs hot and your room its in is cool you will have condensation. You don't have room for a dehumidifier and even if you did it would add even more heat to your grow.What speed fan do you have as it should replenish the air supply every couple min. at least. What is probably happening is the moisture is clogging your carbon and slowing your out going air thus escalating your problems. Simple answer is more air exchange. If the air inside your tent isnt warmer then 15 degrees then outside your tent and your fan pulls at least 250 cfm you should be ok unless you live in swamp land. I hope this helped bro.

The fan is 440cfm on a controller to about 50%. The light in there is a 400w on a winged reflector just because my air cooled 600 hasn't arrived yet. Apparently the humidity level in my house in general is high so maybe a dehumidifier for the rest of the house will help? I'm going into my 2nd week of flowering and really want to resove this before the bud really starts forming. Thanks for your help though I have opened the slats on my tent for now

Depending on strain I would worry yet. Flowers don't really start forming till about 30 days and bud rot wont be a concern till about 40 days in. Just watch out for powdery mildew. There is no doubt r.h. over 65% will cause slow growth as the plant has a hard time transpiring so uptake of water and nutrients will decrease giving warning that they are not growing as vigorously as they could be. On a good note you are also keeping your stretch down for the first weeks so if you get it under control by the 4th week you could finish strong. I don't know if your noob or not but remember to pull hot air from the highest point you can and fresh air from as low as you can. I have alot of hvac friends and you wouldn't believe how much cfm loss can be contributed to excess ducting something to keep in mind. Cfm rating is open ended.