Yeah draining through that tube is the best way to go even though it takes what seems like forever lol. The Voodoo juice could work for you I wouldn't waste it. You could always use it later? I'm going to compile a thread & log of my entire grow experience with AutoPots on this next cycle. I have a brand new 4 pot system coming in the mail today so I'll be transplanting 4 creamsicle plants into there from the same momma and using 50/50 coco perlite as a medium.
Nutrient companies tend to make their biggest money off their Supplements & Additives more so than their base nutrients. I definitely can vouch that hydroponic growing is definitely more tricky than soil almost always. Soil CAN be tricky depending on brand, personally I had horrid results with Fox Farms Ocean Forest and Happy Frog 2 years ago. They were infested with bugs from 2 different vendors in 2 different counties and had some odd PH issues that kept causing me to have overly alkaline runoff which was weird..
Anyways I have learned growing in mediums like Coco gives you the Hydro results but without the technical difficulties and you can treat it more like soil with additives etc unlike in true deep water culture where there are many more variables to keep track of.
Definitely earn your $ back before you switch to anything else, also always try things out. You never know the Voodoo juice might be fire I've had no complaints about any Advanced Nutrients products I Just know that even the CEO recommended another companies product over his and I do know that there are much cheaper alternatives that work better and in smaller dosages. Now remember too though Cheap isn't always better big difference between Cheap and Inexpensive to me at least.. Cheap usually you get what you pay for.
Keep in mind if you're doing Recycling DWC you will likely have more temps in your water from pumps etc.. Be prepared to look into a chiller. One of my friends who is near me in Michigan grows using Heavy 16 full line of nutrients in basic bubble buckets and he gets epic results. IDK how because I tried and couldn't swing it. I prefer COCO but to each their own method for sure.
Autopots can be finnicky too and do require experimentation mainly with how you prepare the pots prior to enabling the system. Medium used, ratios of coco or perlite and also some people fill the bottoms with clay pebbles or rocks/perlite but I do not plan to do that. I'm just going to run a 50/50 blend of coco and perlite so the plants can get a nice wet/dry cycle and feed frequently.
I'll make a note to update you in a couple weeks when the system is up and running. You got this.