water tank question

rocco611 · May 30, 2019

For potable water , I currently have a 1000 gallon translucent plastic water tank I insulated it with foam board and covered it with tarps to keep the water cooler and protect against algae growth. I am considering building a steel 5000 gallon tank or buying a 5000 gallon plastic one. If my well goes dry in the future or I have to work on the pump again 5000 gallons seems to be the right size for water delivery they can bring 4000 at a time leaving me a 1000 gallon cushion between deliveries. with a new housing development going in and quarry as well , the future of the shallow aquifer I am in is questionable. If I build a tank from steel I am wondering if I should build it from galvanized steel and seal the weld joints with cold galvanized spray or build it from bare steel and epoxy coat it inside and spray the outside with automotive paint. I have also considered building a concrete tank. suggestions appreciated

Industrial Toys · May 30, 2019

Is stainless out of the question? I have had stuff galvanized. I like the process but would have zero confidence in that spray. Can't you get a huge poly or fiberglass tank? That would be my first choice.

ddbackhoe · May 30, 2019

You can probably get 2 - 2500 gallons cheaper than one 5000. Aren’t you guys (ca) heavy into rain water harvesting? You can always filter. Any grants available?

rocco611 · May 30, 2019

Industrial Toys said:
Is stainless out of the question? I have had stuff galvanized. I like the process but would have zero confidence in that spray. Can't you get a huge poly or fiberglass tank? That would be my first choice.

I perfer to work with stainless but cost is about 4x the cost of 1018 steel plate. If I could find reasonably priced stainless I would definitely go that route

Industrial Toys · May 30, 2019

Any chance of buying a SS tank off of a scrapped truck?

RedNeckRacin · May 30, 2019

Why wouldn't you hook smaller tanks up to a modular manifold? you can then add or subtract tanks as needed?

Diggin It · May 30, 2019

ddbackhoe said:
You can probably get 2 - 2500 gallons cheaper than one 5000.

RedNeckRacin said:
Why wouldn't you hook smaller tanks up to a modular manifold? you can then add or subtract tanks as needed?

And if a leak develops, it would be easier to isolate and repair, or to replace one tank.

dfkrug · May 30, 2019

You are right to be concerned about the translucent white PEX tanks.

I built my 5000-gal tank of concrete using ICFs, then contacted a big steel tank maker (King City, IIRC) to find out what to coat the insides with. I wanted something that had an NSF-PW rating for drinking water. Whether galv or plain steel, you will want full-coverage coating, in and out. It looks like black tar.

Many folks around here are required to have 10000-gal storage, so get a 10000-gal tank. Note that over 5000-gal, a permit and engineering may be required for the foundation (slab).

fitterski · May 30, 2019

Concrete would be cost effective. 1000 gl prefab sewage tanks come to mind at around $800. Or, 700 gallon (4'x8') prefab culverts can sometimes go at bargain prices if chipped and not acceptable for gov. contract work. I found some for a couple of hundred bucks each. It's a modular solution. Stand them up underground on end plugs first rimmed with sealer, devise a top seal according to needs and pipe them all together. Not sure about sealing the walls for potable water, I don't think I would fret much about that.

WranglerX · May 30, 2019

I installed two 2500 gallon tanks for my 5000 gallon standby... Green poly, and opaque....Think pricing came out to about 50 cents a gallon for tanks (memory a bit foggy on that one)...

Bungs on tanks are 2 inch NPT.... Also installed a hydrant (2.5 inch NPTH) so if engine needs to connect for fire prevention ... I'm a little above you near Yosemite so fire is always in my thoughts... Most people seem to prefer plastic up here....