Hello GC, I have a DIY 16 gallon bubbleponics setup going and I'm having considerable difficulty with keeping the water temperature down to the reasonable 65F - 75F range. The ambient air temperature is 75F, however the heat generated by the submersed pump can easily push the water temperature to 90F if not kept in check every 36-48 hours. This is killing my oxygen absorption rates. I'm forced into doing a half res flush and refilling with cold water until I match 65F. Aside from the extra time commitment, this method significantly increases the cost of nutrients. I've even tried ice in a sealed bag but the size of the res demands a lot of ice to correct the temperature. Should I try and find a more efficient submerged pump or perhaps an external inline or should I jump straight into frankensteing a compressor out of an old mini fridge? Thanks in advance for your help!
a chiller or probe chiller.... their expensive... i found a cheap chiller probe once... wish i could find it again... this should be the only option if your going to grow full time with such high temps
I don't know how good you are with fabrication, but I personally love challenges like this. as far as a mini fridge's compressor goes, that will probably be way too much strain on that little compressor if the water is getting to 90F. It might work for a while, but those things really don't last long, and are made for very low work loads. Get a small fan, like a computer fan, a small power inverter or old power supply for a computer. You can get the power supplies at your local junkyard for free. Modify it so you can switch it on and off. There is a plug with 20 or 24 wires on it. A green wire will be the hot wire and the black wire next to it will be the ground(backwards from house wiring, I know). Connect those together to turn the power supply on. It will have to be on for the small fan to run obviously. Now attach that fan to a small radiator, preferably a liquid cooling radiator for size. Also, either use your current pump with a couple of T fittings in the lines, or attach a separate pump to the computer power supply. You now have a liquid cooling set up for your bucket. I would put it on a timer to go on every say 6 hours for 30 minutes. If that is too much, try 12 hours for 30 minutes. If you can get a digital timer, that would be even better, because you can make it go on for 1 minute every hour or so, which will keep the water temperatures much more steady.
You need a radiator made of a material like titanium or stainless. The soup is so caustic that it will react with most metals (and in the process kill all your plants). Some have used a coiled up length of plastic tubing in a bucket of cold water (kept cold) for a cheap DIY chiller.
They heat up the soup. Makes the chiller work harder. Worse without a chiller. You learn all about root rot and slime. I learned the optimum temp for the soup to get the maximum bang out of my grow (64 deg F).
what kind of pump do you have going? I have a $12 pump I bought for small ponds at lowes and it does not heat up my water one bit Do you have a bunch of black lines exposed to light? If so that is your problem. People even use black hoses coiled on their roof tops as solar water heaters. If you don't think it would be that much of an impact think about that. Perhaps foil tape the lines and lids if not already done. Black absorbs heat like a mofo. Dunno if that helps. Also the larger the rez and the more water it holds the less of an impact your pumps heat it generates will make. There is definitely something wrong with your setup if the water gets hotter than the air around it.
The soup acts like a big heat capacitor. You pump heat into it and if it doesn't have a place to get rid of it, it stores it up. Want proof? Fill a container with water and let it come up to room temp. Drop a pool thermometer and a submersible pump (running) in the container. Measure the temp after 24 hours. If you want to know what your looking at with a grow, wait a week and measure the temp.
now this is good info... i wanna try this now... how do those under current systems battle heat??? im thinking of building one...they use inline pumps.. does this give me a reason to not build it without a chiller?
Inline pumps do not (usually) expose the heat generating part (the motor) to the liquid. If you do some research, you will find that most "serious" hydroponic growers use a chiller and their grows are in the low 60's(F). I use foggers (2) and each one of those pumps about 15 watts of heat into the soup.
Yeah I have a cold temp advantage now but am already looking into an inline that is external for when the summer sets in. I found a nice one for about $40 does 265 gph which is far more than I need. I'm only recirculating and not worried about generating current with it. I had an idea though to put my air pump on my ac register to see if that would pump cold air into the water
are the buckets covered? try duct insulation from home depot or lowes.its sticky on one side,1/4 inch thick foam,and foil outer.its working very well for me,much nicer root system and stays cooler by 10 degrees or so.rez temp 65f.
i hada cloner once that used a submersible pump, thing only held 3 gals so the pump heated the water up to much. i fixed it but using one of the mechanical style timers where each section on the dial was 15 mins, had it run for 15 off for 15mins 24/7 kept my water temp in check and still kept the clnes mosit enough to root, maybe a quick cheap fix. it may not get you from 90 to 70 but for a $5-10 timer that you may already have laying around might be better than nothing for the time being.
Wouldn't the nutrient solution react with the metal insides of the chiller? I am about to get a chiller for my DWC unit but I use Dutch Master ZONE. I had a metal thermometer probe in the tank. As soon as I took the metal probe out, the white slime development on my airstone stopped.
The "good chillers" have a heat exchanger that is made of either stainless steel or titanium so they won't react with the soup.