@Seedfork
According to
https://gardenandbloom.com/blo...
a four inch pot holds 473 ml or one pint. My four inch pots are a bit larger [taller] and most hold 750 ml or a little more than a pint and a half.
I used Miracle Gro 24-8-16 soluble fertilizer about once every ten days or so.
[edit]
The size of the pots is determined by the size of my plant lights for tests during the winter. There are two light setups and each is 4 x 2.5 feet or 10 square feet of space. The number of pots I can put under the lights is determined by their size (diameter) at the top of the pot. Four inch diameter pots means I can use nine pots for each square foot of lights. I can use 90 pots under each light or 180 pots in total. This year I will be using taller plastic "tree" (4" x 14" - volume listed as 0.8 gallons or 2830 ml or 2.83 litres) pots to give the plants more soil volume (about four times the soil volume). Last year I tried "waterproof" tall square cardboard "pots" but they became unglued at the seams after some months of use.
