Which kind of material can I use to build a big flexible tank for potable water?

Question

Thank you very much to everybody.

I do not need a big flexibility but I need a material that doesn't change the taste of water. Someone talk to me about polyisoprene, a natural flexible material (maybe derived from latex). Do you know something about that?

Answer 1

I am not sure how much flexibility you want to use. If you are very handy with tools and stuff, you can try framing with aluminum, reinforced with nylon or steel wires and polythene (HDPE) sheets properly glued (or thermal welding or bolted) inside this frameset. You will get the best of all worlds. The steel/alumium frame will give you the necessary rigitity (as I said I am not sure of what you mean by flexibility). Nylon or steel wiring will give you the tensile strength and polythene will give you the inertness for holding water.

Answer 2

If you are building it, use stainless steel. Stainless steel won't change the taste of the water like some plastics do. Glass doesn't change the taste either, unless the water is exposed to constant sunlight.

Answer 3

I've had to store water for off-the-grid remote houses several times, and in terms of gallons-per-dollar there is no way to beat rigid tanks (of various sizes ranging from 20 gallons on up to thousands) that are commercially available from inumerable agricultural supply stores. Just go to the Yellow Pages, shop around and make your decision. Be sure to specify that it is for POTABLE water.

However, you said you wanted it to be flexible, and for that I think you are going to have to get creative. If it needs to be sealed alll the way around, how about a brand-new waterbed?  If it is OK to be open to the air, then a liner designed for an above-ground swimming pool should work.

In any and all of the above cases you'll want to filter the water going in to remove sediments, and (most importantly) filter the water coming out before you drink it! There are numerous brands of such filters that will remove any and ALL potential contaminants... which is definitely something you must do before drinking any untreated water that has been stored in any sort of tank (potable or otherwise.)

There are small ceramic based filters available from sporting goods stores (usually in the camping department,) and there are reverse-osmosis filters availabale from home improvement centers and some warehouse stores like Sam's Club.

Both types can be further researched on-line using Google. Have fun with your project.