Watering Times Indoors under CFL's

I’ve got some seeds in soil that Im starting in a home designed growbox that incorporates two 5500k CFL’s and 4 small cpu fans. Temp avgerage is 74° F. When I water, should it be at the beginning of the day cycle or night cycle?

Watering should always be done at the beginning of the light/day cycle.

happy growing,


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Should I wait until the soil is completely dry before I water? Its looking like it will be 1 day water, 2 days off. Does this seem legit?

To add: one can use finger test to see if a plant needs to be watered. A plant needs time to dry which also help nutrient up-take many feed 2 out of 3 days and water on the 3rd day and then let dry for a day. Green House Seeds say’s they let their plants go without watering for a number of days (3-7 days) if you let your plant dry for 3 day and then feed it you will really notice the plant explode. For ore information watch one of the video’s they have about growing their strains, they let soil grows go for 1 week dry period

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I agree with this last statement in as much as it is generally 2-3 days between waterings in a 3 gallon pot. This will vary from potsize to size, and will also be different for a young plant as opposed to a vigorous flowering plant.

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OH yeah. When you water in a plant totally; lift it a bit to gauge the weight. Do the same when you find the pot almost completely dry. It will weigh a lot less, and after a couple weeks or so; You will get the hang of it. :slight_smile:

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I’m not sure if it is entirely clear, but Latewood is describing the most commonly recommended way to water plants grown in potted containers.

You should only water when the soil is nearly totally dried out, but before the plant begins to wilt, you should be able to tell this by the feel of the weight of the container, And so when you do water, you water all the soil in the container to saturation, so it should feel very heavy, and then you don’t water at all again until you feel the soil is nearly totally dried out as by the feel of the weight. This is very healthy for the roots and promotes lots of needed oxygen to the roots.

Happy growing,



This is exactly the info I was looking for! Thanks everyone for the invaluable input. Sorry for the delayed response. Im having to mow yards to make ends meet and this is eating up my life!!
On another note…
My growbox is quite kickass! As soon as I can I’ll post some pics with specifics…

This information was very helpful to me as well, I am learning so much from all of you. My older sister grows, and told me to transplant my girls in the ground throw some miracle grow on them and water them and just let nature due its thing, I like be in the city, I just can’t do that, plus I am OCD, I need control.

Thanks a bunch,

Even in early veg stage, I’m a beginner and I’m so afraid of over.watering . I’m in day 13 of my white widow fem, and I’m using cfls

The only difference between lights and the way the plants use water is – how much heat is generated at the top of the plants, or their leaves, and the overall heat in the room – from the lights, and the actual PAR (Photosynthetically Active Radiation – wavelengths/frequencies of light that chlorophyll can use) and how much that will increase transpiration (the plant’s evaporating the water from its tissues through its pores – stomata – and as well as the increased gas exchange that increases the processing of water in the action of photosynthesis and the resulting chemical reactions).

Generally CFLs cause the plants to grow slower and use less water because of not producing as much PAR at the leaves, and also a little due to generally not creating as much heat, as a HID light like HPS.

Yes, the best way generally is judging the water in the soil by the weight of the container.

It will feel super light usually way before the plant starts to show any of the normal signs of needing water, i.e. slight loss of turgidity (the leaves and such start to look a little droopy, if caught right away at the beginning of the slight droopiness, usually there is little to no harm done).

The biggest concern with overwatering is a lack of oxygen at the roots, this is why letting the soil nearly totally dry out and letting that air get to the roots is good for the roots, allowing them and the soil to absorb as much oxygen from the air as they can before the next watering.

This is also why DWC is highly aerated and the roots don’t drown even though growing into a lot of nothing but water. In fact, the same “bloated droopiness” that is a sign of overwatering in soil is a symptom of not enough dissolved oxygen in the water or at the roots in a hydro system.

Happy growing,


One thing I always had to consider was my fans. if for some reason the air from your fans is aimed more at your pot and/or soil as opposed to flowing through your canopy only, then I find that soil loses moisture alarmingly fast.