Greetings Jiggly,
Every journey starts with a single step :o)
Most grow rooms are designed around a certain growing method or style. I would build a soil based (big pots) plant type room different then I would design a room for a
sea of green in planting beds. You also left out are you building only a flowering room or is this a shared space with your vegetation?
You are certainly going to get a yield variance only using a single 1000w in that large of space with your outer plants getting much less lumens. Also your intensity will be greatly reduced because a single light hood will need to be high enough to cast light at 6' high on the outer plants main growing tip. The further away from plants the light is it loses 50% of its intensity for every foot away from the plants. Of course it can't be too close without having a sealed ventilated hood or a liquid cooled bulb. Either the light neds to be raised and lowered to maintain that intensity or the plants will need to be put on elevated platforms then lowered as they grow. Of course the later part of the veg stage on indica or indica hybrids isn't that critical, but on sativa's you have to keep the light intensity high on them without burning them of course, to avoid stretchy internode growth.
I would use two 600w HPS over a single 1000w anyday. In a 15x15 you have room for more lights which will increase your yield greatly,.. up to a point and dependent on the strain and your growing expertise.
I also noticed you don't have any timers listed for your lights, or intake/exhaust, and with a CO2 system that is crucial. I do see you have a controller to turn your CO2 on, are you investing in the climate controller with a co2 monitor ? As that has the timers for your intake/exhaust fans as well as turning on/off the co2 supply. A wise investment.
I noticed you didn't list any plastic for your room, something like a 4mm Panda plastic or white with a black backing to create a sealed barrier in your room(all walls, ceiling and floor). Also to reflect as much light as possible, mylar sheets are a nice addition to the center of the walls to add more reflectivity. I can go into the many reasons to fully plastic your room, but the best is to keep bugs out and smell in. You will want a Hepa Filtered intake(screens at home depot work) and a carbon filter for your exhaust with a fan that has enough cfm to create negative air pressure. What you are trying to create is a sealed room similar to what they create to remove asbestos. I use industrial spray glue to tacky up any place where I use contractor grade duct tape on seams. I also use tape and glue over every staple hole and when you staple, don't staple directly to the plastic as it will tear, put the spray glue/ tape combo on the plastic and staple the tape. I have used wood screws on 1"x3" pieces of thin wood for hanging the ceiling piece of plastic, and that is taped and sealed to the wall, and the floor piece is sealed to the walls finishing the barrier. Once you get the ventilation system working, it will feel like a professional grow room, not a plant on a wood crate with a light bulb hanging in the basement with barren walls.
Soil tips: Changing your plants pots - You will want to transplant into larger pots as your plants grow, and don't jump from a seed into a 50 gallon pot. As a general rule if the plant is twice to three times as high as the pot, time to transplant to a larger pot. Seedling pot, 4", then 12", then 5 gallon bucket, then to a final large size pot or a grow bed. Use a mycorrhizae inoculation when you transplant for some awesome root development. Use a good soil-less mix like sunshine mix or a good organic soil like
foxfarm with bat guano and earthworm castings. Invest in a ph pen, a PPM pen, and a ph soil meter. When you feed them water and root stimulant test the drained water for PPM and PH to make sure you are at your target amounts for the life cycle your plant is in. Use the soil meter to spot check the soil, but there is no substitute for testing the flush water. Learn when to only water and when to feed, over fertilization and ph problems are the number one sources imho of growing problems. Let your plant use the water and dry out but not to the point of wilting. Look at the leaves, they will be up waving in the breeze with their tips pointed up when they are happy and droop or sag when they are sad.
I noticed you are missing circulation fans, but you at least had the light cooling fans(ducted or pointed at the bulb). You need to lift the CO2 off the floor and spread it around your plant leaves. The leaves should constantly be moving slightly, not like a hurricane. :)
Cooling: A small portable AC that you can duct in or duct the heat it makes out, would allow you to raise your CO2 levels, otherwise your heat will rise fast causing your exhaust fan to be on too often to allow your plants to enjoy the massive boost.
Some people will start with a small grow and expand it as they go. Being a medical patient you have a large network out here that will assist you, but be careful as advice can be a double edge sword. I am sure you have heard the old mantra, but never ever let anyone that isn't growing in your grow room know about it. I have several friends who grow but they don't see what I do and vice versa unless we are working together.
I could be preaching to the choir, but wanted to look out for my fellow patients with the friendly advice and tips. Feel free to ask any questions, I'm not in this for profit and glad to share the knowledge.
Most hydro shops charge a premium over internet prices and they deliver to your door. Since you are legal, you don't have to worry as before mail ordering nutrient and grow equipment. Google is your friend, comparason shop. Ebay is a good reference for many items but not always the cheapest if they charge for shipping. Many ship for free at a cheaper price and I have found a few ballasts cheap.
Peace
