under current how many is to many?

I am wondering at what number do I stop building one system and move to 2 smaller ones.
I am considering a 12 bucket undercurrent system 6 strains. As I put more strains in a system there is less custom feed scheduling and a lot more risk if one gets sick. so I am wondering if it is wiser to go with 2 six bucket systems or may be go with 12 but only do 4 strains.
I am also wondering about spacing I will be working with 3 600w in tubes, I figure 6 plants on one side 6 on the other with 1 light every 4 plants 2ft spacing both across and length ways. Any suggestion or input?
I don't know much about hanging the light vertically lower in the center of the plants vs above and horizontal.

Its really up to you, both have advantage and cons. With 1 system you can have a standard feeding schedule for all plants but manual feed or foliar feed those who need more and still have 6 strains but more job for you, and probably cost less? With 2 systems you get less job and more reliability if one break up you still have another.

a 12 site would work, but if you want to do different strains, either get strains that have similar needs, or separate them into 2 systems. You could do 6 of each, or you could do an 8 site mono-culture undercurrent RDWC and then 4 individual DWC buckets with individual strains, or something like that.

I found 2 8 bucket systems to be best. DIY is cheap with even 2 systems it was alot less than 1 system from current culture. Check out my thread its full of info for how to build them & u will get a good idea of my bucket spacing, etc. Any further questions feel free to pm me man

https://www.rollitup.org/grow-journals/579152-under-current-16-plant-2400w.html#post8216254