Noob to hydro, first attempt at NFT system

[brandonbelew]

I've been thinking about making some reflective panels to go around the outside of my grow box, to keep the light in. Heat would become an issue then I fear. The hps might put off too much heat as is. I'm going to have to get creative on the cooling in that room if it does. There is only one floor vent in there.

[brandonbelew]

My new light came in today

It came with a MH and hps, I figured starting with the MH would be the best course of action to promote the plants vegetative growth, then switch over to the HPS when they get bigger.

I also put a fan in the room, as I assume this thing will increase the temperature a bit.

Also started monitoring humidify, it's been sitting at 50-60% in the room.

Do you think I should have my light higher or lower? It's a 600W light, 67,000 lumens on the MH.

Thanks!

[GpsFrontier]

3-4 feet from the plants should be fine as long as it's not to hot for the plants. A 600 watt bulb puts out more heat than a standard 400 watt bulb. You want the air temp at the plants foliage to be between 80 and 90 (preferably 80-85). Well at least for most varieties of strawberry's. There are cool weather (northern) varieties that don't tolerate heat well and would prefer temps closer to 75-80, and varieties that do tolerate heat that will do fine up to 100 degrees. It depends on what varieties you have.

[brandonbelew]

Thanks! I moved the lights down as close as possible. It's an air cooled hood, so I was able to move it a bit closer ( it's about 3' give or take a few inches ). The issue i'm running into now is the light is heating up my nutrient tank, it was sitting at 80 yesterday when I checked.

I picked up a sheet of insulation and put it between the tank and light to see if that would make a difference.

I'm also going to have to change the angle of my light I think. I have the lamp facing the same direction as the plants now but the reflector doesn't seem to be putting out the same amount of light on the edges as the middle and i'm overshooting the tubes in the opposite direction. So i'm thinking about rotating the light.

The plants seem to be loving the new light though. They are starting to bush up a bit more than they were previously with the T5's. The plants on the ends are leaning towards the light which is why I want to rotate it.

[GpsFrontier]

Now you see why I would have opted for using multiple lights points for a more even coverage, rather than a single light source. But still a 600 watt light should be plenty for the small 4x4 foot space your trying to cover. If raising the light up to cover the area better works, you shouldn't have any problem with light intensity (lumen drop) with that 600 watt bulb as long as you don't go beyond 4 feet. But if you can rotate it for better coverage and get it at 3 feet, that would be even better.

Direct heat from the lamp to the reservoir can be a problem in itself like you mentioned, but the reservoir temps will usually be close to the ambient air temperature even if you block heat from the lamp. In other words if the light is raising the ambient air temperature in the room, it can indirectly raise the reservoir temperature through the air temperature as well.

[brandonbelew]

I don't think the ambient temperature will be too much of an issue come summer when the AC runs for 12+ hours a day. Right now it will only run for maybe an hour a day, if that. My backup plan is to run 6" flex duct to the nearest window and exhaust the heat from it.

For now I bought a couple one liter bottles i'm going to freeze and put in during the hot part of the day to see if I can maintain 70 ish on the temperature without cooling it too much.

[GpsFrontier]

I know the plants aren't really big enough to be drinking much water right now, so you don't want to dilute your nutrient solution as the ice melts. But when they get bigger and start drinking up more water, you can just replace the water their drinking daily with ice blocks. That at way you can do both (add ice and water) at the same time, thus help keep the nutrient solution cool, while topping off the water volume.

P.S.
Depending on how much ice you add daily (frozen water volume), you may want to pH adjust the water before you freeze it. If not, it can change your nutrient solution pH. Depending on the pH of the water source and volume of water your adding in ice daily, it can change the pH fairly quickly. If you pH adjust the water before you freeze it, you won't have that problem. To make it easier, I'll pH adjust about 5 gallons of water at a time, then freeze it a few blocks at a time (using cleaned out butter or whip cream tubs) until I'm out of room. Then just use the ice blocks as I need them, and their already pH adjusted. There's been a few times I have even frozen nutrient solution, so when I added the ice it also added some more nutrients to the reservoir. I did so because I wanted all the water I added back to be ice because I needed the cooling effect, but I also wanted to add some nutrient solution back as well. So I just froze it first.