I think you should describe your first two grows so that we can help you not make the same mistakes. That, or be sure to post details of your current grow so we can help you.
Would be a shame to invest so much into a grow and lose it halfway through.
For sure,I understand your worries.i have learned from my past mistakes(there were a lot)
sit down with a bong and get ready for some of the worst growing story's ever.
first grow- high school(young and dumb)
got some bags of miracle grow soil,perlite,little fine sand. I had a 200w UVA/UVB bulb for my old pet chameleonLOL.
Luckily I actually had a decent hookup in high school so I talked to a friend and he got me 5 purple kush seeds.
started them in paper towel ,I diddent know about soaking them in distilled/ro water at that time.
surprisingly all 5 seeds start,I put them in 4 inch plant pots with the crappy soil mixture mentioned^.
i went heavy on watering them because they kept drying out,i don't know why?(the fucking heat lamp lol)
One of the 5 rotted and never popped above the soil.so now I have 4 left.
I put the sprouts in a south facing window with the UVA/UVB bulb above them,about a week goes by and my friend(who knew abit about growing)told me I have the kind of bulbs/light.
i went and bought some sunblaster t5ho fixtures and some cfls,they were doing alright considering I was using miracle grow liquid fert along with the MG soil.
i transferred them to 6inch pots,they experienced a lot of stress at this time,so I though they need water,lots of water.
i killed two with root rot over the next week or so.
at this point I built a shitty tent/room in my basement and started setting up t t5's and cfl's in it.(3X2 room)
i diddent think about ventilation I only had a small 4 inch fan running at the base of the tent bringing in fresh air,and a 5 inch oscillating fan in the room to move air and strengthen the plants.
i had some vent holes on the top and side....
seemed like a decent setup(in my head)
About four weeks later the plants were like 10-12inches,not great growth and showing lots of nute burns(but I was a noob and thought the over feeding was actually something the plant was missing,so I kept adding random fertilizers to try to fix it)
I put them into my shitty shack 12/12 lights mostly 2700k lights some 5400k
Forgot to mention I diddent now how to sex a plant,so I was just going to put my two in the room and hope for the best.....
One week in I was concerned they weren't growing much,and no buds yet!
obviously I needed to buy AN bud blood DUH!
i burned those plants so bad one died over night the other one came back slowly over the next week.
but I started watering the plants so much and my ventilation sucked so much that eventually a week later my last plant died from root rot,I weren't feeding fertilizer at this time,just lots of water.
first run I never PHed,or checked TDS
Grow 2
So I realized I was a complete noob,did a lot of reading over the next year and a half,I started vegetable gardens in my back yard(great practice,and I learned organic gardening,still learning)
i thought I figured out most of my problems,over watering,over fertilizing,not enough ventilation,cheep soil,and I wanted better lighting.
i had two bag seeds from some really really good hash plant(only one s female,both started)
so even though I had zero experience with DWC I had read so much I KNEW what I was doing,lol.
I used that same crappy tent I built a year and a half eariler(how lazy am I?diddent even take it down lol)
I installed a 4 inch high powered fan with a cool tube for my 400wMh,and I installed two of the same fans in the shack,one sending in fresh air on the bottom of the tent,the other sending hot air out the top.
Heat was not an issue this run,over fertilization was
i veged in this room I was using a 5 gallon for my dwc,I went to a crappy store and a guy talked me into buying gunnisse fertilizer(grow,flower,micro,bee one,royal gold)
i found it was high in salt content,and had unnecessary dyes in it.
i was using hydroton in the basket,with a top feed system running from the pail bellow on a timer.airstone in the bucket(I know controversial)
i worked out my watering schedule so I wasn't keeping it to wet or too dry
everything was going alright it was 20 inches when I sent her into flower with a 600wMH
But again I kept over feeding with nutes and I kept burning the crap out of her(oh ya at this time I could find a male or female right on!)
I burned her once in veg,once again in first two weeks of flower(bud blood),and I finically killed her off fourth week of flower from nute burn.
this run bugged me the most because I was changing the water twice a week,cleaning the bucket/rocks.
i was doing everything right except for was over fertilizing(was using liquid ph tests for aquariums,worked well)
and a tds meter,but I was following the grow chart too closely and used way too much ferts.
Third grow- year later
I decided to scrap the DWC because I'm still learning the basics.
Back to soil I used black magic organic soil(might only be available in bc)perilite,greensand,little glacial rock dust(at this point in time I diddent know synthetic ferts,killed off the benefits of organic products)
i still had that Guinness fertilizer so I gave away the royal gold and got royal black for soil.
my friends said a good starter plant is northern lights so I ordered 5 seeds.(4 started,3 were female)
i way cut back my fertilizer all the way through veg,and flower,I received nute burn once week three of veg,not bad
I veged them for about 4.5-5weeks,I hear most people like to veg northern lights for 80-100days(ill know next time)
i flushed for a week,diddent know much about flushing,and I left the lights off two days before I chopped them down.
i diddent do anything fancy(no training or topping) but this time I made it thought flower YA! wOOHOO
now came the important part,curing I had done a little reading on drying and curing
I cut all the main branches off and hung then on string in a dark closet corner of my basement with some fans on timers.
after I felt they were ready,when the stems bend and snap but there is a small layer of outter fiber holding it from fully snapping off.
I diddent get a huge yield so I took the buds off the stems/branches and put them all in a big dark Rubbermaid tote,opening the lid for an hour two/three times a day.
i got 65.5 grams dried medicine from all three plants averaging about 21.8g each plant,I know not great but it tasted pretty good
i am not currently growing,this thread was started because I am starting to build my new room soon so I can start up again
of course with Co2 enrichment you can turn up your temps and light and plant will be able to absore more, but then I would go for 2x600W with some nice cool hoods and a big 8" ventilation 
.its not about the price it cost to produce its about mixing all spectrums to try to get the best quality medicine.
