Watering

Bro ! You just need to pour enough water until they don’t soak up, take out the excess of drain, lift your cups and water again when they’re not that heavy anymore.

As organoman said them cups are terrible to grow in.

5ml is nowhere near enough and those cardboard cups suck the moisture out of the soil rapidly and are not really suitable for cannabis seedlings. I tried them many years ago and found out that they take ages to break down and let the roots out and I needed to cut slits in them to allow the roots through. Secondly, to get them to break down they need to be close to saturated all the time, something we all know cannabis does not like. I would suggest black plastic pots, about 4 inches across and about 5 inches deep as being the ideal size for about 3 weeks growth of cannabis seedlings, with enough room for good root development and enough room for the soil to provide enough nutrients without the need for extra feeding. With those cups you are using I found keeping their moisture levels correct and at an even level almost impossible, they went from too wet to too dry very quickly. The only way I found to beat the problem was to transplant the seedlings and throw those cardboard pots in the garbage with joyful satisfaction. Standing the pots in water until the cardboard was wet was the only way to stop them drying out too quickly, but the soil gets too wet by doing so and giving 150ml of water from above would work for a while but then they dry out too quickly again. These style of pots really are a nightmare! I too thought they would be great and easy to use when transplanting, but they turned out to be a disaster and were only tried once. Enough said really! Hope this helps in some way, Organoman.