I used a spare light that I was originally using to help differentiate between colors with tank test kits. The light has a 13 watt “full spectrum, daylight” bulb.
I used 3L bottles because I had them and they were clean. I’ve seen people use 2L bottles, 1 L beakers, water pitchers, etc...
The bottles I used aren’t recommended because it’s preferable for the bottom of the bottle to be round to help keep the phyto from settling on the bottom. I was swirling the liquid once or twice a day to help keep the phyto in suspension.
As an experiment, and out of courtesy to the other half, I left two sealed bottles of phyto on the counter, still being lit, and both bottles are starting to turn clear and are staying clear; the phyto is settled on the bottom. My guess is that the phyto hit maturity and is starting to die without co2.
I put three 16 oz bottle of phyto in the fridge and the liquid is green in all three without being shaken. Phyto is supposed to stay alive for a month in the fridge. You should be able to split the refrigerated phyto in a couple of weeks - at least that’s my hope.