I am growing my first plant. I have four in it's own pot each inside a 20 gallon fish tank. They are still pretty small, but I was wondering what size fish tank is the best and also if a 20w floro-gro bulb is good enough. I also have a 60w compact HID bulb and was thinking about using that as well. Would this be to much?

I also saw some of the posts about doing hydro and saw some pics. This option might be better for me, all I need are the fish, I have everything else.

Also how long should I wait before I take them out of the pots and plant them in soil I plan on using a pan with holes on the bottom for the plants for drainage and watering inside the tank with cpu fans for circulation.

Why do you have them in an aquarium? It serves little to no purpose to keep these plants enclosed in glass. They absolutely don't like the humidity.
Your lighting may be sufficient for now, but will soon be woefully inadequate. The sun's output is approximately 10,000 lumens/sq. foot. Unless you're lighting with an arc welder (or similar), there's no bulb that can beat that. If you were growing plants that require high humidity then growing in an aquarium makes sense, but this is not the case with Cannabis.

You don't "need" fish to grow hydroponically, it's just another method by which to grow hydroponically.

I grow outdoors, but know about lighting and water because of my aquatic experience (which is why your thread title caught my attention).

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Where i am you can't easily grow outside. (small city, police, thieves). I was hoping to grow on the low, a tank seemed practical. I was just actually looking in my closet trying to think of ways to prop up lights. I also saw a picture with aluminum foil. Should I line my walls with that?

You want something reflective, so even painting some boards white would help I would think. In my own experience aluminum can break down, that was with a saltwater tank. The lights could make the inside of the tank too hot, that's my first concern. Plus, the plants don't seem to like high humidity.

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Use mylar sheeting. It won't break down and it is an extremely efficient reflector.

When I was growing full-time, I used 3000 watts of HPS light. It's expensive power-wise but I was harvesting close to 1lb every two months...

^^^^1lb shit man thats 0.14933...gpw 1gpw isnt unheard of u sure u had hps?

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i dont see why i should be the criminal
how can somethin with no recorded fatalitys be illegal

fish tank will be ok if you cover the glass dwc is nice and simple just make a lid for the tank with holes for net pots fill the pots with hydroton or similar and put shitloads of air stones from a nice big airpump in there with your nute soup. DWC simple but v. effective

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i dont see why i should be the criminal
how can somethin with no recorded fatalitys be illegal

We used 3 1000 watt bulbs over an 8'x4' plastic lined plywood tray. Ebb and flow. Clones in the closet under fluorescent bulbs. 64 ladies in the tray in pots filled with lava rock. Plenty of air circulation. No added CO2 but we spent hours and hours in the garden working and breathing so that mitigated much need for supplemental gasses. No pests to speak of human or otherwise.

It was beautiful! Did that for two years and eventually moved on. It's real honest work and if done with the appropriate level of discretion and attention to detail cultivation can be extremely rewarding.

I realize this is now off-topic but it's worth knowing especially for those thinking of using an aquarium. It's not a good choice. I'm unfamiliar with the gpw abbreviation. Clarification please. Thanks.

gram per watt

__________________
i dont see why i should be the criminal
how can somethin with no recorded fatalitys be illegal