Use pots made from squarish containers such as plastic water jugs, etc. More hemp plants will fit in less space and have more rooting area if square containers are used. This makes your garden a recycling center, and saves you tons of money.
2-liter soda bottles work great, but are not square. 13 will fit in a kitty litter box, and these will take a 3 foot plant to maturity hydroponically. If you can get 4 litter boxes in a closet, you can grow 52 hemp plants like this vegatatively. Spread them out more for flowering.
Old buckets, plastic 3-5 gallon containers (food and paint industries, try painters’ and resturant dumpsters), paper paint buckets, old plastic garbage cans of all sizes, and garbage bags have all been used successfully by growers.
Do not use paper milk cartons and juice cartons for reservoir hydroponics, since these are difficult to sterilize, and they introduce fungus into your reservoir trays. Inert materials, such as plastic is best.
Be sure to sterilize all containers before each planting with a clorine bleach solution of 2 tbspn. of bleach to one gallon of water. Let container and meduim such as rockwool soak for several hours in the solution before rinsing thouroghly.