Variac Fan Speed Controller

I own a 6" Hurricane Inline fan that has a rating of 435cfm. Does anybody here have good recommendations for a variac fan speed controller? I did some research and the cheap ones don't cut it. I am willing to spend upwards to $100-$150 for a viable controller.I got my eyes on Titans Control Mercury 4. What do you guys/girls think?

Please and thank you! Oh, my grow tent is 36" x 36" x 60"

I came to the same conclusion -- the reviews for the cheap ones on Amazon basically say they're great if they work; some of them don't. I ended up buying a used "Staco" brand variac (search for "variable transformer") on eBay for about $70. It's old and has some rust spots and dents, but it's all metal, made in the US, and clearly high quality. There are tons of models, you'll have to search for one that seems appropriate. (In particular, I don't see any reason to get one that's rated for lots of current -- the fan can't draw that much; mine is a 5 amp model, which I think is the smallest. And they are made for a range of input voltages; mine can handle both 120V and 140V -- not sure who uses 140V, but the 120V setting is all I need.) Good luck.

this one. $55, handles up to 3amps


https://www.amazon.com/PHC-Enterprise-Variac-Variable-Transformer/dp/B006NGI8VS/ref=sr_1_1?ie=UTF8&qid=1487096060&sr=8-1&keywords=variac+speed+controller

Made my own out of a dimmer switch from home depot