DWC with a freezer to cool reservoir

[raphie6]

I'm planning to grow indoors in a DWC setup but my room temps are around 95-105 Farenheit, i've being thinking about ways to cool down my water temps, and being wondering if buying a small freezer that sells for around 90 bucks and drilling two holes, and start circulating water between the freezer and the reservoir can help lower my water temps, i dont want to buy chillers. And also i would really be interested in knowing wich strain is best for high humidity high temp places. Any help will be appreciated!

 

[FuzzyGrnMnstr]

Hello Raphie6,

To start, room temps of 95~105 is way to hot even for strains that like it hot. Your stomata will be doing ZERO work at those temps, and will greatly reduce overall yield.
Using a small freezer will not work either, the principal on how they work dose not correlate to removing BTU's for a system that is subjected to constant effect. That is why they have actual "chillers" for hydroponics and aquarium use. Essentially if you used a freezer, it would be in constant over drive to keep the constant BTU abuse down, using a TON of electricity and eventually killing it... Fast... Your few options are, Chiller for use of removing heat, Add ice... or what I have done with great success was implement some IT skills and used a sweet 9-140mm-fan radiator used for pc water cool systems.

 

[PrairiePoet]

While Fuzzy is right that you need to drop the air temps down around 80 or so.

But I disagree with using a small freezer or mini fridge to chill the reservoir. I've done it and you can find others in the DIY section. Once it gets the res down to the proper temps, it stays there, with the fridge coming on about 15 minutes every two hours, keeping two 10 gallons tubs at 78 degrees.

 

[raphie6]

Thanks fuzzy and prairie for the quick reply, its my fault that i didn't mentioned enough. I'm planning to build inside a closet, 4X8 feet and 10 feet tall, temps are really high but only in the day time, my thermometer has pointed up to 105 but with no ventilation at all. here is a drawing of a top down view of my idea.

from top down, the yellow rectangle is going to be enclosed so that heat from the freezer won't interfere with my babies, the freezer is the green square, inside the freezer i'm planning to put a little reservoir (blue) that is going to be circulating with my main reservoir (brown) inside i'm planning to put circulating fans, and the red rectangle is going to be an exhaust, its going to be placed above the freezer so it wont interfere.

the freezer i'm planning to buy from w-mart

prairie gave me some ideas for controlling temp if it gets too low i'll try connecting the freezer to a timer, thanks.

 

[PrairiePoet]

Thanks fuzzy and prairie for the quick reply, its my fault that i didn't mentioned enough. I'm planning to build inside a closet, 4X8 feet and 10 feet tall, temps are really high but only in the day time, my thermometer has pointed up to 105 but with no ventilation at all. here is a drawing of a top down view of my idea.

Very similar in how mine is.

Except my fridge is out side the closet (hiding under a nearby table). Tubing between is insulated with that grey foam tubing you can buy. I wrapped the tubing around the freezer part then out to the closet, into a small tub with a pump on one end. From that, I have a pump for each grow tub, pushing the water into wort coils inside the grow tubs. Three pumps total. I did test to ensure a single pump can push the water through all the tubes. All in case a pump goes out, I have backup. The meters are checked twice daily, so if a pump goes out I'll know in 12 to 24 hours.

I do not run nutrients through the pumps or tubing. I have, but after one grow you need to replace or clean the tubing. This works better. The water is mixed with a cup of bleach to 4 gallons of water to keep out any growth and slime.

I've ran this setup through two grow cycles. It keeps the temp right at 68 degrees, with minimal adjustments. The fridge is usually set at 1 or 2, the lowest settings.

I want to go back to what FuzzyGrnMnstr was saying. You do need to get the freezer's exhaust (most likely a radiator on the back or bottom) and keep that away from your grow. My grow is in the basement so the ambient temp is almost always around 75. So I would suggest you create an active exhaust pulling air out of the grow closet and away from your intake for the plants.

otherwise good luck dude.

 

[raphie6]

thanks Prairie you've given me some good ideas, and one last question which strain would be best??

 

[PrairiePoet]

thanks Prairie you've given me some good ideas, and one last question which strain would be best??

Should be fine with about any strain. Hard to answer without knowing more of your grow area/room and/or other methods (SCROG, SOG.....)

I was running a sativa strain with SCROG, that I was told was called OG Chocolate. Though I don't think it is, but certainly sativa. Since I clone from a mother, auto's are out. I could go indica, and plan to next grow.

 

[WillyBudz]

I used to have a a setup similar to this.

Room temp was 82-85f and res was a pain to keep at 68-70f.

Went to Sam's and bought a 150qt (37.5 gallon, 30 gallons used) igloo cooler, took top off and replaced with 2" insulation board wrapped in Mylar and aluminium tape. A slot at then end is cut out to add /check nutes, check res temp and swap the frozen 2 ltr every other day.

I grow 6 plants in 30 gallons now and drop 1 frozen 2 liter in it every other day. Res temp stays between 65-69f, after 3 days without a change it might get hot and get up to 71. 4 days is 72 etc... etc..

I check plants every day and it takes all of 5 seconds to xchange a single 2 ltr for 30 gallons every 48 hours or so.

Electric bill from freezer went away, not much but about $12 month and I can use my freezer for my sauce... errr beer now.