actually, I thought the water temp was too low, when i put a meter on it, it turns out it’s too hot. Fortunately, I haven’t bought anything yet. System is a sealed recirculating. 3 inch basket’s inside of a 4 inch pipe.
I agree with @Just as an initial attempt. You can put together a cheap cooler this way pretty easy w/ some spare parts. Check out Google for ‘diy swamp cooler’. If you find that you don’t get enough cooling from this your next step would be going with a small external chiller.
from what i’m seeing, swamp cooler’s will drop the temp of the grow room. The room fluctuates between 20 and 26C. I don’t want to drop the temp of the room, only the water. Also, I have no spare parts to somehow make a fan blow on the water so i’m spending money regardless.
So you have a rez that is a separate container, then pump the water through the pipe and it drains back to the rez?
I am assuming the rez is inside your tent or grow area? If so, a better solution would be to move it outside the grow space. That way it wont be subject to the heat from the lights. If you are growing NFT in tubes, then you dont need or want a lot of flow, so any losses from extending the pipes from the pump to the tubes wont matter.
Also, if you have the pump inside the rez, that will be heating the water - maybe a lot. Change over to an external pump will help.
So after thinking on it for a bit, i realized I have a few computer fans kicking around. Currently converting 1 of them for this purpose, have a few more i can add and it’s a power supply fan, almost twice the size of the little guys.
So this is how it sits now. Have to give it a few hours to see the temp. I also had the air pump sitting on top before because of hose length. I have more hose now so I moved it beside in the shade instead, temp of air pump dropped immediately so that should help too. Thanks for the suggestions 
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Unfortunately, I doubt this is going to do the job for you. Its largely a question of power. but also you need to think is terms of pumping heat from one location to another.
First, lets talk power. Air conditioner/cooling units require power to move heat from one place to another - like the inside of a freezer to the outside of a freezer. Your computer fans just dont generate enough power to move a significant amount of heat. Aquarium coolers for example generally run 1/10th horse power or more. Your fan is drawing maybe 1 watt. A real chiller is going to be using 1/10th horse power which is around 75 watts, so your fan is under powered by a factor of 75. In other words, you would need 75 of those little fans to equal the power of a typical chiller designed for a 30 gallon aquarium. On top of that, cooling your rez is a lot more work because the room temp is so much higher than normal.
So, from a pure power stand point, you’re not even in the ball park.
The second part of the problem is your not MOVING the heat anywhere the way you have it set up. The fans would need to blow that air somewhere else for any cooling to happen. Just circulating the air inside the rez will do nothing, because the heat isnt moving away from the water. It just circulates right back.
Also, the only real way for a fan to cool is through evaporation. The fan is supposed to carry away warm water as it evaporates, but yur setup has no place for that warm water vapor to go except right back into the water. You will get zero evaporative cooling with that setup.
For a fan to work, it would need to be much larger, blowing a LOT more air and it would need to blow that air someplace else other than back into the rez. It would also need to be blowing cooler air onto the water than the water temp for it to work well at all.
Your best bet is to:
1 - move that rez completely OUTSIDE the heated space. That alone may solve your heat problem.
2 - change the water pump so it is outside the rez. Water pumps add a LOT of heat to the water. Most aquarium pumps can be converted to work either way, but it depends on your pump.
3 - moving your air pump was a good idea, but it would be even better if the air pump was also outside the heated space.
In order for a fan to cool your water the way you are trying to do it would require a much larger fan = much much larger. It will also have to take cooler air from outside the grwo space, blow it into the rez chamber, then ideally. it needs to be piped outside the grow space again… For sure it needs to exit the rex itself or you will get little to no cooling.
Remember, you need to move the heat from one place to another, AND that take POWER.
Its is more efficient to not have the heat in the first place - which is why I am telling you to move the rez and move all pumps outside the rez.
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I might be able to move it outside of the light area but the entire basement is more or less the same temp. So far it only seems to be making a 1 degree difference. The air can sorta get out of the rez just because the handles aren’t sealed. Unfortunately, buying another pump is just not an option. For now, look’s like i add what fans i have, maybe point a couple of smaller ones towards the actual holes and keep my eye’s open for a cheap bar fridge
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Nice looking setup!!
What water pump are you using? Many of the more popular aquarium pumps include all the parts you need to convert them to external pumps - nothing extra to buy.
Almost forgot - are there any basement windows or vents to the outside? You might be able to run some cheap flexible ducting to pull in fresh/cool air and exhaust the hot air.
there’s windows, but i’ve sealed them up so that the entire town doesn’t know i’m growing
This bad boy is my pump, Stupid pet shop told me i needed a utility pump so yeah. I think it moves 130l/m or something like that.
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New rez location…
And just on the other side of that door is -30 air. Too bad I built a wall so I could keep the basement warm enough in the first place
Had ice down here last year…
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Put insulation around your tank and piping. That will stop heat entering during the day and leaving during the night. The more stable you can keep your rez, the better your plants will grow.
If you need to cool your tank, I would suggest getting a hailea H150 or similar for your size of tank, if it can be somewhere relatively cool that does not put the heat back into your tent/growing space. You will need a 1000lph pump for it also.
Make sure your nutrient temp does not go below 18C, use your aquarium heater for that.
Try to keep air temps around 26C during the day and 22C during the night, you may need a heater on a thermostat to make sure of this. Again, this stability will give you extra growth, yield, and quality.
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No aquarium heater and the heat source is the furnace. I’ve got the entire house flipped around for heat. The basement is the hottest part of the house and the upstairs is the coldest. The rez was sitting at 25C when the light comes on, the only time it drops below that before now is cause it was fresh water.
So I’m trying this. It’s obviously reduced the amount of flow considerably. In the bottom corner of the door is the only air leak left in the basement. I’m hoping this will work for now…
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As long as the roots stay wet, I think the lower flow will be fine. NFT is nutrient ‘film’ not nutrient ‘flood’. Less is more with this technique. Other wise its just DWC with more pipes 
If you could get a loop, or two, or three of that hose to run outside where its -30, you would have an instant free chiller! You would need to be sure the flow never stopped though, or the hose would freeze.
Edit: I just had a thought. if you built a small insulated box up against that door where the air leak is, you could put the roll of excess hose inside it. Leave the side of the box against the door un-insulated. The air leak would cool the water in the hose but there would be far less risk of freezing.
EDit 2:
That explains a lot. Its going to make things more dificult. if you can start planning to incorporate some of @MicroDoser suggestions for the next grow, that would be good. They are all excellent suggestions.
And of course the light decided it didn’t want a night cycle. When the light should have come on, temp was 27 C. Unfortunately, the rez is away from the light but closer to the main heat for the basement. I’m going to use some carpet I have lying around to make a wall which should make the entire area with the rez in it colder.
A further note about the heating system. The grow has it’s own vent (stolen from an upstairs room). There was a service port more or less in the middle of the basement. I have removed the cover. This has made it so more heat goes into the basement then anywhere else in the house. I originally did this last year because the bottom half of the main floor was always freezing. Obviously all the temp’s fluctuate. On average the basement is around 24C, the main floor is around 21C and the upstairs is more like 16C. One final note, the thermostat for the furnace resides on the main floor beside the kitchen. This creates it’s own issues like whenever we cook, the furnace doesn’t run.
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