How to: Mildew proof grow room?

(I also posted this in: SICK PLANTS section)

Hello GC Doctors!

I am currently finishing up my first grow attempt. It was fairly successful; 1 platinum og & 1 blackberry kush. 2 seperate DWC 5 gallons. 400w hps + 125 cfl hydrofarm light. I started in a 2x4x6 tent. I studied, read and watched a ton of youtube videos before I started, so I decided to get a portable a/c unit. For one it cools no problem, second, I read that a/c is a great dehumidifier. But come to find out that the a/c isnt always pumping in an area that small, so it wasn't always dehumidifing. Around this time, I moved into a larger 5x5x7 growtent. (they were at the top of the 6' tent) When I first noticed the white powder mildew, (about week 4 flower) I put in a humidity gauge and was shocked to see the humidity would reach 65%-70%. So I immediately bought a dehumidifier. I also bought Zero Tolerence to spray areas after I clipped them.
So I have been doing all I can after I discovered this. As I, like I'm sure all of GC's loyalists, treat their plants like children. (...and I don't mean getting sticky by touching them!!!)
So right now I am clipping any branches that I think will be more problematic than other areas, because they ARE probably ready, or at the earliest stage of being ready. The hairs are at least 70% orange. I'm sure the trichs are a little on the clear/cloudy side instead of cloudy/amber. But I'd rather have a little underdeveloped bud then, nothing by losing it to mold.
But my main concern now is: For my next grow I don't want to deal with this problem again, so I am planning on bleaching, Zero Tolerencing out the tent, cleaning the filters on the a/c & dehumidifier, keeping the plants under 6 feet tall and un-bushy ( I already lollipopped the next 2), and having the dehumidifier from the start. I live in the SFV north of LA (prop. 215) where the climate is desert (yes desert) it's rather dry year round except January.
So QUESTION: Should I be cool this time around? I feel like the problem never got completely fixed because, although the humidity problem was fixed, I think the white powder was just hiding and spreading.

I have a pre-98 bubba and a platimum og going in a seperate 125w cfl tent ( my old 2x4x6 ) And I don't want to put them in the tent if the same will happen. I am also debating just CFL'ing the entire grow to see how a CFL does. I will add the other 125w for a 250w CFL total. When I get the tent cleaned and whatever I got 8 clones going from the pre-98 & platinum so I want to veg them under a 400 MH then hopefully I will have a 1000w HPS I've had my eye on. Also planning on DWC, probably 6 to stay prop. 215 legal .

If anyone has any input regarding this, it would be really helpful. Thanks in advance.....