SWFL
Guest
Have an order to build a two tank hydroponic system, in total there will be three tanks, a 7.5 gallon reservoir​ and two 5 gallon tanks that will hold two 6" mesh pots each.
Now the most common method for building such a hydroponic system is to use 5 gallon buckets, however they don't lend themselves well when it comes to attaching plumbing, being round they are hard to cut a useful thread into them and a failure of such, lacking a retention system can become a real problem.
Because of that I prefer to use RV water storage tanks, they are relatively inexpensive and can be purchased with molded in or properly attached standard National Pipe Thread (NPT) fittings, another advantage is unlike buckets they having flat sides which are easy to insulate with expandable foam ,which is very important in hydroponics to maintain proper nutrient temperature.
That stated on to the build, the first step is to wipe the tank down with mineral spirits to remove any left over mold release compound, once that is done and flashed off I build a dam to retain the expanding foam using aluminum duct tape.
Once completed I mix the proper amount of two part 2 pound closed cell expanding foam, I use closed cell foam as it is resistant to absorbing most anything and is strong enough to support the tank when filled with liquid nutrients, another reason I use it is the R factor/value which is a measure of the foams ability to resist heat flow​, with the closed cell foam I use it is around R8+ per inch, I normally get around 1.5 inches which is equivalent to R12 insulation.
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The foam I use is mixed 1 to 1 ratio and I poured 12 Oz total.
Once poured the tank is tilted side to side and front to rear to spread the mixture as evenly as possible, in about five minutes at 80F or more it begins to expand in about 5 minutes.
Continued next page.
Now the most common method for building such a hydroponic system is to use 5 gallon buckets, however they don't lend themselves well when it comes to attaching plumbing, being round they are hard to cut a useful thread into them and a failure of such, lacking a retention system can become a real problem.
Because of that I prefer to use RV water storage tanks, they are relatively inexpensive and can be purchased with molded in or properly attached standard National Pipe Thread (NPT) fittings, another advantage is unlike buckets they having flat sides which are easy to insulate with expandable foam ,which is very important in hydroponics to maintain proper nutrient temperature.
That stated on to the build, the first step is to wipe the tank down with mineral spirits to remove any left over mold release compound, once that is done and flashed off I build a dam to retain the expanding foam using aluminum duct tape.
Once completed I mix the proper amount of two part 2 pound closed cell expanding foam, I use closed cell foam as it is resistant to absorbing most anything and is strong enough to support the tank when filled with liquid nutrients, another reason I use it is the R factor/value which is a measure of the foams ability to resist heat flow​, with the closed cell foam I use it is around R8+ per inch, I normally get around 1.5 inches which is equivalent to R12 insulation.
The foam I use is mixed 1 to 1 ratio and I poured 12 Oz total.
Once poured the tank is tilted side to side and front to rear to spread the mixture as evenly as possible, in about five minutes at 80F or more it begins to expand in about 5 minutes.
Continued next page.
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