Ideas for using 15,000 L of water (in a tank)? - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: September 11, 2016, 03:49:08 am
content: As part of government requirements for building new homes, I was forced to have a 15KL water tank installed as part of construction (the size depends on the footprint of the house). This was the smallest I was "allowed" to have.However I primarily use town water. Outdoor taps, toilets and optionally the washing machine are all plumbed to this 'recycled water' tank via an electronic valve. Normally the valve connects these outlets to town water and when there is a pressure drop (i.e.: you turn on an outdoor tap, flush a toilet etc...) it switches to tank water and engages the pump. (It's deliberately done this way so you still have mains water in the event of a power failure).Now, I hardly use this tank water except for washing cars, hosing off hard surfaces or watering the garden. I basically live in the bush so there is a lot of eucalyptus (and other) oil which leaches out of gum leaves into the tank water. Over time, it causes build-up and stains in toilets etc... so for the sake of saving a few dollars (clean town water here costs AUD$2.00 per kilolitre), I just switched off the electronic valve/pump and use clean, filtered water.This means at any given time, I have 15,000 litres of water just sitting in a tank. When it rains, it overflows into the back part of my property (which isn't really an issue in itself as it's just bushland anyway).Can anyone come up with any ideas on what I can actually use this water for? Giant water feature perhaps?

author: Brumby
author_rank: Unknown
timestamp: September 11, 2016, 03:58:32 am
content: I had no ideas until you mentioned "water feature".Now I have no ideas about whatsortof water feature.

author: Lightages
author_rank: Unknown
timestamp: September 11, 2016, 04:13:59 am
content: You have a fortune sitting in that tank. All you need to do is add one 1/100000000 of a drop of any medicine and then you have the most potent medicine of its type. You can sell 10ml of that water to all the homeopaths in your area for $100.

author: Ian.M
author_rank: Super Contributor
timestamp: September 11, 2016, 04:30:47 am
content: That sounds like the valve system's crazy!Logically the purpose of the tank is to minimise non-essential potable water usage, so the town supply should feed the outdoor taps etc. via a check valve followed by a N/O solenoid valve held closed by the mains, via a low level float switch in the tank, and the tank pump should have a pressure switch, be fed via the same float switch and keep pressure on the feed to the outside taps using tank water. That way it only cuts over to the town supply if the tanks low or there is a power cut. Drawing from the town supply via a simple check valve then cutting the pump in on a pressure drop sounds like a cheap-skate recipe for a lot of water-hammer.Can you put in a 50 gal drum gravity feed sand/charcoal filter on the tank outlet to remove the worst of the oily contaminates? I'd also consider a diverter system on its inlet that discards the first 5 minutes of any rainfall to let contaminates wash off the roof before you start capturing water.The issue with any water feature will be mosquito lavae. Done wrong it could make your property virtually uninhabitable.Have you considered using it for an emergency firefighting supply? You'd need a self contained water pump with engine (preferably diesel) and 100m of large bore fire hose

author: Halcyon
author_rank: Unknown
timestamp: September 11, 2016, 04:36:14 am
content: Quote from: Ian.M on September 11, 2016, 04:30:47 amI guess that's another way of doing it. I suppose the way they did it is the simplest of systems. No water level switches to go faulty etc... It is literally only the pump (which is a good quality Davey pump) and the diverter system.As for water hammer, it's pretty much non-existent in this house, at least anything that's audible. All the internal piping is that plastic stuff (PEX?). Outdoor taps and anything beyond the internal walls are made of copper.Quote from: Ian.M on September 11, 2016, 04:30:47 amI have and it's probably what I'll end up doing in the long run, I do live in a "bush fire prone" area. However my property is probably down the lowest end of the threat level, even in the hottest of summers. I only have bush to the rear which is mostly made up of damp fern forest. The foliage is so thick that it's pretty much in a constant state of "moist" (damn, I love that word). Beyond that the bushland is fairly wall spaced so even if a fire did rip through there, it would be relatively low intensity with reasonably low flame height.

author: mtdoc
author_rank: Super Contributor
timestamp: September 11, 2016, 04:41:37 am
content: Reservoir for a very large, water cooled electronic load?

author: CatalinaWOW
author_rank: Super Contributor
timestamp: September 11, 2016, 04:50:08 am
content: That is a lot of thermal mass, and fairly easy to couple to it efficiently. Seems like it could be put to use making your heating/cooling more efficient.

author: Brumby
author_rank: Unknown
timestamp: September 11, 2016, 04:51:50 am
content: Quote from: mtdoc on September 11, 2016, 04:41:37 amNow that's a good EE idea!

author: Ian.M
author_rank: Super Contributor
timestamp: September 11, 2016, 05:14:45 am
content: Quote from: Brumby on September 11, 2016, 04:51:50 amIf you've got of the order of 5 GJ of energy to dump, you could bring it to a rolling boil which would almost certainly help with the contaminates. However I reckon its a good thing you've got the pump switched off as I think a boiling 'hot flush' could be rather disconcerting! :exploding_toilet:

author: mtdoc
author_rank: Super Contributor
timestamp: September 11, 2016, 05:21:52 am
content: Quote from: CatalinaWOW on September 11, 2016, 04:50:08 amAlong those lines, we have a large septic tank that sits underground, adjacent to our greenhouse. One project I have on my agenda is to couple the heat it produces to the greenhouse to extend our growing season. A closed loop system with a solar PV powered pump is what I have in mind.

author: kripton2035
author_rank: Super Contributor
timestamp: September 11, 2016, 06:11:51 am
content: frog pool ...

author: EEVblog
author_rank: Unknown
timestamp: September 11, 2016, 06:20:34 am
content: Quote from: Lightages on September 11, 2016, 04:13:59 amYep, get in while it's still legal!

author: Ian.M
author_rank: Super Contributor
timestamp: September 11, 2016, 06:28:06 am
content: Stock it with enough Electric Eels to power its own pump . . . .

author: Ampera
author_rank: Super Contributor
timestamp: September 11, 2016, 06:53:23 am
content: Quote from: Halcyon on September 11, 2016, 03:49:08 amI'd roll it over to the top of a slanting street, and just let it all out in an instant. Won't cause chaos, but for some reason that seems fun to me.

author: SeanB
author_rank: Super Contributor
timestamp: September 11, 2016, 07:09:29 am
content: Get a heat pump hot water system and use the water tank as a heat sink, running the AC in heat pump mode in summer to cool the house. Much more efficient than pumping heat out to ambient, and will last a lot longer than trying to use a refrigerant to heat water to 70C, where you run the compressor at a very high head pressure with the reduced life of the whole unit. Instead you are pumping to a sink that will likely be only 2C above ambient all the time. All you need is a smaller submersible pond pump to move the tank water through the condenser side of the heat pump.

author: Brumby
author_rank: Unknown
timestamp: September 11, 2016, 08:24:20 am
content: Quote from: TwoOfFive on September 11, 2016, 06:53:23 amThe OP hasn't stated one way or the other, but these water tanks can be installed below ground - so that might make yours a difficult option.

author: Ian.M
author_rank: Super Contributor
timestamp: September 11, 2016, 09:35:35 am
content: Get in a ****ing big refrigeration plant and a ski resort snow machine and have a white Christmas!

author: Halcyon
author_rank: Unknown
timestamp: September 11, 2016, 10:00:58 am
content: Quote from: Brumby on September 11, 2016, 08:24:20 amMine's above ground. It's roughly 3.2 metres in diameter and 2.4 metres tall. Considering it's 15+ tonnes, rolling it down the road might be a little tricky. ;-)

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: September 11, 2016, 10:22:45 am
content: Water the garden or grass, then refill it when it rains.

author: Halcyon
author_rank: Unknown
timestamp: September 11, 2016, 10:24:38 am
content: Quote from: HackedFridgeMagnet on September 11, 2016, 10:22:45 amI can't use it fast enough on just gardens and lawn. We get a decent amount of rain in the Blue Mountains with some fairly mild summers. That amount of water just isn't needed.Maybe I could make a giant slip'n'slide down the road when it gets warmer? Hmm...

author: R005T3r
author_rank: Frequent Contributor
timestamp: September 11, 2016, 10:29:34 am
content: Why on earth your government is obliging you to have 15.000L water tank? it doesen't make any sense...

author: TerraHertz
author_rank: Super Contributor
timestamp: September 11, 2016, 11:22:38 am
content: Quote from: R005T3r on September 11, 2016, 10:29:34 amAt times Australia can get very dry, and the dams supplying Sydney can become critically low, especially with the stupidly expanding population of Sydney. So there were water use restrictions, raised prices, public campaigns to make people save rainwater and use it for garden watering, etc.But that was then, and recently the weather is much wetter. And will remain so for years, if Mr Maunder and his spotless Sun has anything to do with it. Currently all the dams are near full:http://www.waternsw.com.au/supply/dam-levels/greater-sydneys-dam-levelsThen there's the AGW religious resistance to any suggestion of the climate becoming wetter for decades, because of course all climate change is baaaaad. So there's no rollback of the water use rules and pricing. Maunder glaciation will proceed faster than legislation change.As for using it...Firstly the brown stain is tannin, from gum leaves. In concentrated form it can be used to tan leather. I'd rather drink rainwater with tannin, than town water with chlorine and fluoride.If you have somewhere on your property significantly higher than the house, you could put a second small tank there, with a small solar powered lift pump from the big tank. Then use gravity-fed water from the small tank for most house use, rather than town water. Showers, bath, toilets, etc. Filter for drinking and cooking - remove the tannin, still no fluorides.Manual valve switchover to town water if there's been insufficient solar pumping and the small tank emptied. Keep it simple.Insulating the main tank and using it as a thermal mass for house air-con is also a good idea.Then there's the bushfire drench system. Something I plan to do when/if I move to the country. Not so much to save the house (mine would be fireproof anyway, partially underground), but to preserve surrounding trees. The idea is to spray drench everything in sight, before the fire front arrives, so nothing burns. Obviously, must be a diesel driven high capacity pump, since the town power would probably be out in such a situation.If you already live in a moist fernery, there's probably little point to this.

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 11, 2016, 11:36:23 am
content: Get a second tank, same size, and mount it 100 ft above the first one. Then use solar power to pump the water from the existing one into the higher one. When you want some power (like at night) operate it in reverse through a dynamo.I saw a great video about this technique on an island where they have mountains and a lake at the top.How about using old oil wells for the same purpose but in reverse - let the sea water in to generate power, pump it out when the solar / wind is working. Infrastructure already in place..back to reality..I suppose it would maintain a fairly even temperature throughout the year.

author: R005T3r
author_rank: Frequent Contributor
timestamp: September 11, 2016, 02:12:50 pm
content: I swear I didn't know that Australia was one of the driest inhabited country: nobody ever told me... Actually I knew only that there were a lot of dangerous wildlife such as snakes, but I couldn't imagine that there was such a problem about water reservoirs.I've read: an entire dam dropped down to 16%? That's actually insane, at these levels there's no way to produce electricity in a large city... Now it's clear that if anyone stores water there's a good chance that during a drought you may find yourself without water...

author: nctnico
author_rank: Super Contributor
timestamp: September 11, 2016, 04:15:53 pm
content: Get rid of the tank and make a swimming pool?

author: Cyberdragon
author_rank: Super Contributor
timestamp: September 11, 2016, 04:22:52 pm
content: Make a hydroelectric plant.

author: Ampera
author_rank: Super Contributor
timestamp: September 11, 2016, 04:36:03 pm
content: Quote from: TerraHertz on September 11, 2016, 11:22:38 amI honestly don't get the mindset of people who are upset about fluoride and chlorine in the water supply. It's not enough to kill you, and you would sooner die of over-drinking and failed kidneys than you ever would any affects from flouride and chlorine. You ingest MORE fluoride every time you brush your teeth, and heck the people on the ISS have to swallow their toothpaste for 6 months, and they are all fine up there.

author: TerraHertz
author_rank: Super Contributor
timestamp: September 12, 2016, 01:13:55 am
content: Quote from: TwoOfFive on September 11, 2016, 04:36:03 pmIf only your google-fu was as well developed as your programmed kneejerk.http://everist.org/archives/links/__Fluoridation_links.txtJust in case you are honestly curious _why_ some people are concerned about compulsory water fluoridation, that will get you started.Chlorine I agree is not a big issue, but I'd still rather drink water without it, given some other way to kill any pathogens.Oh, also related: One of my hobbies is 'urban exploration', which leads me to sometimes be places where the public is not supposed to go. Which unfortunately I cannot detail here. But I've seen some things that greatly reinforce my anti-fluoridation opinion.Quote from: R005T3r on September 11, 2016, 02:12:50 pmNone of the dams around Sydney have operating hydroelectric plants, the water is too precious to just dump through a turbine. Waragamba dam (the biggest) was built with a single small generator turbine built into the dam base but it's never used so far as I know. Probably only intended for local power in emergency.Woronora dam also had a tiny turbine generator added around a decade ago, but that too is only for powering dam infrastructure in emergency. I don't know about the other dams.The major hydroelectric systems in Australia are the Snowy Mountains system (some of the power to Sydney and Melbourne), and the Tasmanian systems (most power in Tasmania.) Other than that, most electricity is from coal and gas stations, with some wind and solar.