marzig
Member
After growing in soil for three years I decided to take the plunge into DWC late last year. I went with DWC instead of RDWC because of limited space and uncertainty of success. After much research I realized that keeping my nute temps low was my biggest concern. I’d like to share the details on how I cool my two 5-gallon Hydrobuckets.
I have a 2’ x 4’ tent shoehorned into my bedroom closet. Some of the pics are from my first DWC auto flower grow from which I had a yield of a little over 400 gm in thirteen weeks with zero root issues. The rest are from my second grow in which I’m currently in week five.
I have a 120 qt cooler filled with about 8” of water that my two buckets sit in. In between the two buckets is a heat exchange coil I made from 3/8” x 10’ copper tubing. Cooled water enters the coil through ½” id black vinyl tubing and returns to a 48 qt cooler that sits outside my tent. In that cooler is a 160 gph submersible pump, a 1-gallon jug of frozen water, and 4” of water. The pump is controlled by a thermostat with its sensor located near the heat exchange coil. On either side of the coil are two air stones to keep the water circulating around the buckets. I only have to swap the 1-gallon jug at 6am and 6pm.
Obviously there is some lag between the cooled water temp and the nute temps in the buckets. Fortunately this results in very consistent nute temps while the cooled water temp fluctuates as the pump cycles on and off. I have found that a 0.1 of degree temperature difference between the pump on and pump off is ideal. I do occasionally adjust these set temperatures up and down as conditions such as light intensity change. I’m able to maintain nute temps between 66 to 67 degrees. After the lights have been off for six hours nute temps drop to 66 and slowly rise to 67 when the lights go back off. If I’m going to be gone for a day, I just add additional jugs. I always have about 6 jugs ready in my chest freezer.
I plan on staying with DWC as I've noticed that even with seeds from the same cultivar that two phenotypes respond differently to nutes and I can fine tune for each plant. Plus I'm producing more than I can consume myself and end up giving a lot of it to my close friends.
Parts Inventory:
Igloo Polar 120 qt cooler $100
Coleman Cooler 48qt $35
Digiten DTC-101 Thermostat $30
160 gph submersible pump $15
3/8” x 10’ Type L Copper Tubing $20
½” ID x 10’ Black Vinyl Tubing and various fittings $25
Total $225
I have a 2’ x 4’ tent shoehorned into my bedroom closet. Some of the pics are from my first DWC auto flower grow from which I had a yield of a little over 400 gm in thirteen weeks with zero root issues. The rest are from my second grow in which I’m currently in week five.
I have a 120 qt cooler filled with about 8” of water that my two buckets sit in. In between the two buckets is a heat exchange coil I made from 3/8” x 10’ copper tubing. Cooled water enters the coil through ½” id black vinyl tubing and returns to a 48 qt cooler that sits outside my tent. In that cooler is a 160 gph submersible pump, a 1-gallon jug of frozen water, and 4” of water. The pump is controlled by a thermostat with its sensor located near the heat exchange coil. On either side of the coil are two air stones to keep the water circulating around the buckets. I only have to swap the 1-gallon jug at 6am and 6pm.
Obviously there is some lag between the cooled water temp and the nute temps in the buckets. Fortunately this results in very consistent nute temps while the cooled water temp fluctuates as the pump cycles on and off. I have found that a 0.1 of degree temperature difference between the pump on and pump off is ideal. I do occasionally adjust these set temperatures up and down as conditions such as light intensity change. I’m able to maintain nute temps between 66 to 67 degrees. After the lights have been off for six hours nute temps drop to 66 and slowly rise to 67 when the lights go back off. If I’m going to be gone for a day, I just add additional jugs. I always have about 6 jugs ready in my chest freezer.
I plan on staying with DWC as I've noticed that even with seeds from the same cultivar that two phenotypes respond differently to nutes and I can fine tune for each plant. Plus I'm producing more than I can consume myself and end up giving a lot of it to my close friends.
Parts Inventory:
Igloo Polar 120 qt cooler $100
Coleman Cooler 48qt $35
Digiten DTC-101 Thermostat $30
160 gph submersible pump $15
3/8” x 10’ Type L Copper Tubing $20
½” ID x 10’ Black Vinyl Tubing and various fittings $25
Total $225