Polyethylene tank prices vs. gallonage

[bcarwell]

Could somebody give me general guidance on how potable water tank prices go for a raincatchment system which I'm just starting to investigate ? In terms of price per gallon is there much % savings in a 10K gallon tank vs. several 3K gallon tanks ? And if I have the space what are the considerations in two 10K gallon tanks vs. 6 or 7 3K gallon tanks ?
Unless there is a real savings in the huge tanks I'm beginning to think there are a lot of plusses to the multiple smaller tanks. Obvious downside is having to connect them all. But I would think shipping would be the same or maybe even more for the gonzo tanks (I know the smaller ones are only $90 shipping each), they are only 8 feet tall and thus less unsightly, easier to move if necessary in later design changes, I would guess the pads to avoid tank stress might be a little less involved (just a few inches of compacted sand on compacted dirt ?), benefit of being able to shut one off if necessary for cleaning or whatever without shutting down whole system, easier to take delivery on and install (especially down a fairly steep rivine where I'd locate them), etc. Any other suggestions or gotchas before I order them ?

Bob

 

[dfkrug]

Over 5K gallons requires an engineered foundation, if you are concerned
about building codes/inspections.

I don't have current local prices, but I would lean toward multiple 5Ks,
or even 3Ks for this reason as well as those you stated.

 

[MtHam]

We started out 20 years ago with one 2500 gallon tank and it has served us well. Over the years, I have added 2 more, and I love the extra storage and the redundancy. Relatively easy to handle and set up.

 

[boggen]

as long as the water is not for (drinking water) you have a wide range of options.

from regular old "septic tank" being used instead of your house waste water, being used to store water. septic tanks would more likely be geared to be placed underground. but there are versions for above ground as well.

i done forget the correct term for it. but it kinda resembles milk crates. ya dig a hole in ground, put a liner in, snap together these pieces that resembles milk crates, then toss another liner over top of it, then put some dirt over top of it. and seed with grass.

making a liner pond Koiphen.com granted site is geared to having fish in the pond. but a holding pond non the less. and instead of going with more expensive 45mil epdm liner, you might get away with pvc style liner.

i have seen folks get a old semi trailer, cut off the back wheels, toss a liner in it.

i have seen folks take sections of grain bins / silos and sink them into the ground and toss a liner into them.

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if you go with plastic style tanks, order them all at once and have them shipped at same time. and delivery cost can go way down. at least until it requires another truck.

be careful on some of the larger tanks though. some of them may come shipped in sections, and require manufacture to come out and put a main final plastic weld on them. and some may simply require bolts and some sort of silicon / polyurethane to act like a gasket in joints.

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as soon as you move to "drinkable water" or consumption by humans or "potable water" a lot of extra codes jump in. but when water is not used for human consumption, it can be more referred to as "brackish water" or "black water" or "grayish water" and used for watering gardens, lawn, trees and like. and there are a lot less codes and many more options that are cheaper.

as far as what the tanks can be installed on, either compacted dirt with sand, or require concrete. a lot depends on shape of tank and how manufacture set it up / created it. then ya have various codes to deal with as well.

i would honestly google search for "septic tanks" and then look at the various manufacture websites for potable water if that is way you are going. i say search for septic tanks, because it returns more manufacturers quickly vs trying to search for "potable water tanks" and many times potable water tanks only brings back a couple descent links.

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double check for ease for install bottom drain on tanks. to make it easier to clean a tank out. some tanks are down right a pain. and end up having multi lower spots in bottom, that requires a wet/dry vac or something to suck out the nasty water in bottom of tanks, if you need to clean them.

bottom drain, could be a 2" shower drain, with piping to a ball valve, to a 3" or 4" toilet flange used as a bulkhead, to electrical female and male fittings used as a bulkhead, to uniseals, or the expensive actual bulkheads.

i have seen folks take cylinder shape tanks with a cone or dome like top with a flat bottom, flipped upside down, just to make it easier to clean tanks out. granted folks were using the tanks as filters on koi and fish ponds, but something to think about.