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Post by Apoplast on Sept 22, 2015 22:30:37 GMT -5
Hi Lloyd - Copper is also plenty toxic to plants. The key to Avery's beautiful setup is that the metal is properly painted. The same should be true for aluminum, at less cost for construction. Both metals are excellent at thermal transmittance, though copper has nearly double the u-value (thermal transmittance/conductivity). A bigger factor for this type of setup is likely to be material cost and thermal capacitance (do you want thicker metal that will buffer the temperature change of the solution moving through, or not?). Even that is not likely to make much of a difference on this scale.
Essentially, if you can set it up and getting it running properly, Justintime, the choice of metal shouldn't matter much - as long as it is painted. :-)
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Post by lloyd on Sept 22, 2015 22:35:01 GMT -5
I'm not sure how much copper leaches but I know from my measurements that aluminum leaches a lot and quickly. Even water from dehumidifier fins has toxic levels of aluminum and the fins are only briefly in contact with the water.
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Post by lloyd on Sept 22, 2015 22:43:04 GMT -5
I don't know that your plants will be damaged for sure. I just know that aluminum is a plant toxin even though some plants have evolved some resistance. Also I have checked dehumidifier water (aluminum fins) and the aluminum built up to toxic levels (for humans) very quickly.
Copper is also toxic to plants. I know houses use copper piping which lasts a long time, so perhaps copper would leach less.
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Post by Apoplast on Sept 22, 2015 23:01:08 GMT -5
Hi Lloyd - It is totally possible that aluminum has a higher solubility in water. I don't know that off the top of my head. Condensate water, of course, is a bit acidic, so the water from a dehumidifier might be worse on the metal. But you are correct, aluminium can be quite toxic to plants. in fact one of the first cations (frequently metals) that are freed in problematic quantities from acid rain are aluminum ions in soils - the comparison with copper is made more complex because copper is comparatively rare in most soils. Regardless, it is solid evidence that aluminium is toxic to plants.
I still suspect, that proper painting is important in a system like Avery's to reduce the likelihood of metal toxicity of any kind. A physical barrier should prevent the metal from entering the water.
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Post by frederick on Apr 4, 2016 11:27:06 GMT -5
Hi Avery! Your setup is amazing, congrats! I'm thinking of making something along those lines for some highlanders, helis and cool growing orchids in a 20gal terrarium. What kind of paint did you use to coat the copper tubings? I wouldn't want to risk water condensing directly on the copper but some types of paint can also be toxic themselves to some degree. I was thinking of going with 3/8'' copper tubing, sold already coiled, like this one www.homedepot.com/catalog/productImages/400/eb/ebb43885-0c73-4ea3-bbcb-6711abf8f6c3_400.jpgHopefully I'll have less work to do with bending the tube. The fact it is continuous and not assembled parts of tubing is also relieving since I plan on using a water/antifreeze solution. The less joints there are, the best I will sleep at night! So basically it is a closed system, like yours, of icy water circulated by a small water pump, 400L/h or 200L/h. The cold source would be a styrofoam box containing another stretch of coiled copper tubing at the bottom and filled with ice packs and/or ice on top. Vinyl tubing would connect the pump with each copper coils. Here is an idea of what kind of box I have www.mominmanagement.com/wp-content/uploads/2011/01/omaha.steaks.jpg Another idea I had, which I don't plan on testing this summer, would be to install a 100W Peltier cooler on the styrofoam box itself, in addition to the ice packs, which could at least extend the length of time it stays cold in there, if insulated efficiently. The electricity consumption would jump of course, but in theory I believe this could make for a semi-autonomous cooling system. What do you think?
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Post by Avery on Apr 5, 2016 23:10:12 GMT -5
Hey Frederick, I can't really comment as to how that would function simply because I haven't done it. Personally, I strive to have a terrarium as automatic as possible, so that I'm able to travel for work or pleasure without having to worry about my plants. I've left town for over a week without any losses or setbacks (not that I haven't had losses or setbacks...). Having to replace ice daily might get tiresome. I'm nearly done building a new grow chamber. I will post more about it later, but I'm going a fairly similar route as my current one, only I've purchased radiators instead of making my own. That copper tubing is not bent, by the way, it's cut and soldered using 90 degree elbow fittings. The radiators are sprayed with a high-performance enamel paint. Should be fine once cured. Here are a couple of radiators prior to painting them: Also, I don't really have a "closed" loop. The fluid flows right back into the reservoir (freezer) and new fluid is cycled through. Because the end up the line that sucks up fluid is always submerged, the line won't lose fluid and the pump won't lose its prime. As soon as I lift it out of the water, air gets in, the tubes start draining, and I have to re-prime the pump.
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Post by amanitovirosa on Apr 6, 2016 17:04:39 GMT -5
...that looks like it's going to be a very solid setup! No wonder your Neps always look so happy. Nice work man. AV.
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Post by Apoplast on Apr 6, 2016 18:16:44 GMT -5
Hi Avery - Auðumbla (a.k.a. holy cow)!!! One word - craftsmanship! I can barely wait to see the full update. My, completely ripping your design off, setup is going to be a while. Turns out, the bottom glass on my 75gal aquarium was tempered... I need to find a glass shop now.
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Post by kdawg on Apr 6, 2016 20:20:46 GMT -5
Hi Avery - Auðumbla (a.k.a. holy cow)!!! One word - craftsmanship! I can barely wait to see the full update. My, completely ripping your design off, setup is going to be a while. Turns out, the bottom glass on my 75gal aquarium was tempered... I need to find a glass shop now. Sorry to Hijack, But congratulations on your 1000th post Apoplast! Good stuff!
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Post by Avery on Apr 6, 2016 20:55:39 GMT -5
Apoplast,
Thanks, but I didn't make the radiators pictured above, I only soldered a couple fittings on them... Ha. Sorry if there was confusion.
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Post by frederick on Apr 7, 2016 11:57:25 GMT -5
Wow now that's a great setup haha can't wait to see it up and running with your plants!
Thanks for the advice, I'm an indecisive person to begin with and, given I'm not at ease with that kind of endeavor, I'm taking forever to make up my mind on the cooling system I will use lol
Could you tell me what kind of radiators you bought and how many watts they use? This might be worth the extra bucks in my conditions...
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Post by Apoplast on Apr 7, 2016 19:55:49 GMT -5
Sorry to Hijack, But congratulations on your 1000th post Apoplast! Good stuff!
Hi kdawg - Thanks! That really sneaked up one me. I probably haven't had one-thousand relevant things to say in my life. Probably should shut my big yap! But... Hi Avery - They are still beautiful! And all the joints are wonderfully soldered! Because it now looks like I will have to get a custom tank to emulate your setup - I'm going to have to sit one the side lines and admire your genius for a while.
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