i need help with high humidty...(+rep for help)

nothing i do seems to lower the humidity, and i could really use some advice from some wise people that KNOW how to deal with this issue, not just guesses...

grow space: 4x4x6 ft. homebox growlab, 400w HPS, temps are usually 73-77 at night, 80-83 daylight. humidity around 73%. the tent is inside a basement room (about 10x8 ft.). i think a big part of the problem is that just use a small 8" desktop-type fan for exhaust, with a DIY carbon filter, since i couldnt really afford a nice expensive fan, and i cant really afford anything right now. i dont think it really moves the air through properly though. im in week 3 of flower, and ive been trying to get humidity down since i started flowering, but nothing i do works...

i have a large, and useful dehumidifier, but it puts out enough heat that i cant put it in the tent, and i really dont have room for it in there either, so thats no good...when i put the dehumidifier in the room with the door closed, it helps drop humidity a little, but temps jump above 85, so ive been putting it in the doorway, exhausting the heat into the main basement room...thats fine, except it doesnt change the humidity IN THE TENT...is 73% humidity going to rot/mold my buds?

ive tried a couple of DIY things....tried putting crystal cat litter in there with a fan blowing on it, didnt do anything, even built a little case for it and hung it from the ceiling of the tent, didnt work either...

not really sure what to do here....this is my first grow, and the buds are looking great in week 3, but i dont want to lose it all because of humidity.

do i need to bite the bullet and buy a nice exhaust fan and carbon filter, or does anyone have a better and cheaper idea?

exhaust is crucial to control humidity.. that little fan you are using won't do it. You need to be able to clear all the air in the tent in 5 minutes max... at 73% humidity, your plants will probably have mold problems. But as your humidity rises, your carbon filter will stop working as well. at 80% humidity, it won't work at all... And your temps are way to high in the day with that lack of ventilation you are starving your plants of CO2 and you are really stressing your plants. Honestly if you can't afford a fan, you should wait until you can as you are just asking for problems and failure with what you are doing..

you need a better extracter fan m8 normally with high temps your humidity is lower than that and have a fan circulating air in the tent as well cause that will help fight against mold issues as well.
try and keep your room that the tent is in cool if you can because that will influence the temps and stuff inside the tent as well and hopefully have fresh air coming into the room as well m8.

and defo stick at it cause you can just upgrade every harvest and in a few grows you will have and nice setup that suits you

thanks for the advice guys...i decided yesterday that i just need to shell out the extra cash for a fan...im going to try to stick with my ghetto carbon filter for a couple of days and see if it actually works well when there is enough air blowing through it to make it effective in the first place. im going to pick one up today at my grow store.

usually i wouldve bought one from the get go. im a "if youre going to do something, do it right" kind of guy, but my initial start up costs were more than expected (thats how it goes). if i wouldve bought a good fan/filter setup from the start, i wouldve saved myself a few bucks anyways, not spending it on crap that doesnt work ....lesson learned.

ill let you know how it works out, and throw up a couple of pics of the buds in a few days...

i picked up a 4" 178 cfm can fan, stuffed my DIY carbon filter in the tent, pulling air through it, and venting into the next room...seems to be kicking ass right now. ive been in and out of the room tweaking things for a coupe of days, had to find a good way to run the ducting, but i think im good to go now, threw my old little fan i was using as exhaust in a port near the floor for intake. i just watered, but humidity is 53% now, it was down to like 48% earlier, but its been hot and humid as hell here the past week.

so, if humidity in the mid 40s to mid 50s is as good as it will get with this exhaust set up, is that going to keep me free of humidity related problems? i assume it would be better around 30-40, but its going to do what its going to do at this point.

any thoughts appreciated, and as promised, here are some pics (end of week 3 of flowering.)...

*cough* anyone want to tell me recommended humidity levels for flowering? what are "dangerous" levels?

*cough* dehumidifier *cough*

*cough* read before posting *cough*

40% is recomended

not sure what they are called (de-humidifier), but at wally(home depot, lowes) mart they have little pine cone things you fill with a silica type salt and that eats the moisture in the air. i have a few. they help. i can be more specific if needed. if your level is to high anyway.