I use GH 3 Part and all I can say is ONLY USE HALF the recommended dose.
Here are my 3 threads on my 3 grows. All are DWC.
https://www.autoflower.org/f6...row-37161.html
I used a 30 gallon tote and switched to a 50 gallon for this grow.
https://www.autoflower.org/f6...ous-38286.html
two 5 gallon buckets with 8" netpot tops.
https://www.autoflower.org/index.ph...autos-from-nirvanashop-com.42277/#post-818991
Cheapest way is 5 gallon buckets,air pump and air stones. 5 gallon tops with 8" net pots built in. I use the 2 liter frozen bottle method to keep my rez cool but I recommend a chiller if you can afford it. Current Culture has some great DWC stuff also. Here is a link
http://hydrobuilder.com/brands/curre...FYMCaQodgnYAww
Not sure what your budget is. I use General Hydroponic Flora Series It's a 3 part nutrient solution. Grow Micro and Bloom. Then some Floralicious Plus the last 4 weeks of flowering. I use 1/2 the recommend amount and I also use UC Roots. This stuff is the BOMB! My plants are so healthy.
I use 1/2 of the recommended amount and measure for 4 gallons of water cause it's about a gallon subtracted for the netpot. I am using 5 gallon buckets. Just take the length of your auto's life which is about 9 to 12 weeks and breakdown the steps on the feeding chart to coincide with your auto's life cycle. Most nute feeding charts are for photo plants. You just have to improvise the feeding and take care of your girls. When topping off your rez just use plain water and ph after you added the water to your rez. I don't get all caught up in the PPM and all that other stuff. I K.I.S.S.(keep it simple stupid) I use a vile for the water and a 3 drop solution and look at the color. I keep my PH between 5.7 and 6 and it is consistent. Also for the last 4 weeks you want to use some GH Florolicious Plus. Very little but use it. I also use UC roots. I use this until the last week of flowering.This is what I would do for a 11 week grow using General Hydroponics 3 part Flora Series
Seedling 1 week
Mild Growth 1 week
Growth 1 Week
Aggressive Growth 2 Weeks
Transition 1 Week
Bloom 2 weeks
Aggressive Bloom 2 Weeks
Ripen 1 week (I have heard to switch back to a metal halite for potency for the last week too. I did it not sure if it worked or not. I gonna leave the HPS in until the end this time to see if there is a difference.)
Also like I said already K.I.S.S(Keep it simple stupid.) I PH once a week and it might change .1 or.2 which is no sweat. I know I am changing my buckets once a week and I PH after adding Nutes to 5.6-5.8 using a 3 drop solution. I have had 5 very healthy plants with awesome smoke. Don't sweat the PPM and PH to much. You might over think it. I did that a few years ago until my friend showed me the simple way. I saw his grow and WOW. I wanted to grow just like him and now I am. Good Luck!!
