Thread: Hut tank size

Re treatment the house we brought last year had no proper filtering on the rainwater system. Just a first flush on the main pipe to tank and tank has a felt bag on it's inlet. Nothing else. Water tasted ok and no one sick after a few months but we decided to test it anyway as wife was concerned. Low pH so bad for plumbing corrosion and moderate ecoli. Not good! Since then we have been refilling containers from a town supply.
Plumbers quote was $7k to supply and fit pH neutraliser, filters and UV into the pump shed. Buying and fitting it myself for $4.5k :-) There's exposed alkathene pipe in there so easy to fit using Hansen fittings with a short bit of copper pipe and compression fittings at UV outlet. Will cost About $400 per year for replacements filters, UV tube and electricity. $1/day to not get sick is worth it. Hard to do properly in off grid locations though.

stayed in FS and later most were DOC huts for I quess 30 years had water from the tank- never crook but did not drink the water fresh - always a cup of tea- and I guess mouth wash cleaning teeth - so does one need to filter - from all of this I quess it depends on a few factors for your hut - how easy is it to get a number of tanks in there if you want whole hog and showers - flushing dunnys - you will need water and lots of it - but are there other options - any creeks nearby - alternative source for shower and toilet - spring up the hill maybe -pipe it back to hut -then just a tank for drinking water - or no flush dunny just a long drop and lime it every few days nothing wrong with it -although the townie kids might say otherwise - showers those little solar pack ones

Originally Posted by uk_exile

Re treatment the house we brought last year had no proper filtering on the rainwater system. Just a first flush on the main pipe to tank and tank has a felt bag on it's inlet. Nothing else. Water tasted ok and no one sick after a few months but we decided to test it anyway as wife was concerned. Low pH so bad for plumbing corrosion and moderate ecoli. Not good! Since then we have been refilling containers from a town supply.
Plumbers quote was $7k to supply and fit pH neutraliser, filters and UV into the pump shed. Buying and fitting it myself for $4.5k :-) There's exposed alkathene pipe in there so easy to fit using Hansen fittings with a short bit of copper pipe and compression fittings at UV outlet. Will cost About $400 per year for replacements filters, UV tube and electricity. $1/day to not get sick is worth it. Hard to do properly in off grid locations though.

No, not hard but you have to get the right DC LED (new tech) UV filtration system to be able to work off DC off grid power. Benefit is no annual bulb changes with the LED tech, as the LEDs don't suffer the from wavelength shift like the bulbs do as they age.

Originally Posted by Barry the hunter

stayed in FS and later most were DOC huts for I quess 30 years had water from the tank- never crook but did not drink the water fresh - always a cup of tea- and I guess mouth wash cleaning teeth - so does one need to filter - from all of this I quess it depends on a few factors for your hut - how easy is it to get a number of tanks in there if you want whole hog and showers - flushing dunnys - you will need water and lots of it - but are there other options - any creeks nearby - alternative source for shower and toilet - spring up the hill maybe -pipe it back to hut -then just a tank for drinking water - or no flush dunny just a long drop and lime it every few days nothing wrong with it -although the townie kids might say otherwise - showers those little solar pack ones

It's not the townie kids I find, it's the townie moms that moan whinge and bitch until your ears bleed... As far as the filtration and sterilisation, if you get it set up 'right' from the get go it will just work and with the right maintenance you will have minimum issues with it going forwards. Are you planning on running a pumped pressure system or some form of head tank setup?

Funny story, I went to pick up the kid from preschool in town one day, and grab his crap and turn around and he's pissing on the citrus tree in it's pot. Um, excuse you? He looks and me, "bush wees". The lady at the center was trying not to crack up, as she's looking at me like it was my fault. It actually was his dairy farm mom that started that! Shrug, quiet chat about that not really being kosher to do to a tree in a pot on ceramic tiles and away we went.

A number of 2000 litre water tanks are installed in the bigger huts on the TA trail in the South Island. In one case the BCT installed x2 water tanks totalling 4000 litres in 2024. Check out the BCT website /fb to view the various water tank installations and maybe ask advice.

Thanks for the advice so far everyone. Water collection will be off the roof. 44m2 roof which equates to 66000 litres per year available.
Current house supply is off roof so no stranger to that kind of set up.
Farm supply water will be at the hut site for a fire house but non potable.
Was thinking a 5000l tank. I wanted to steer clear of a 30000l track just for aesthetics. Perhaps I could have a small collection tank then solar pump up hill and gravity feed back

I have a 4000l “big water tank” brand tank off a shed for stock water. Nice height (low to get under gutter for gravity feed) can manoeuvre it to move and seems well made. Would seem about right for a hut and use as you described.

I would recommend a floating water take. A guy on trademe sells them. We went 11,000 liters on our holiday pad. No flushing toilet but

Originally Posted by Remmodel7

Thanks for the advice so far everyone. Water collection will be off the roof. 44m2 roof which equates to 66000 litres per year available.
Current house supply is off roof so no stranger to that kind of set up.
Farm supply water will be at the hut site for a fire house but non potable.
Was thinking a 5000l tank. I wanted to steer clear of a 30000l track just for aesthetics. Perhaps I could have a small collection tank then solar pump up hill and gravity feed back

Problem you'll have with that maths is it is not a constant even flow of water off your roof year round. You'll have 66,000 theoretical liters per year but with the way our weather patterns are 1/2 of that will drop at the same time and your tank will not be able to store it. It will drop out the overflow on top of the tank (which as an aside you need to factor in with your groundworks and tank base so you don't end up with a sinking tank or a muddy mess around your hut).

My tank (20KL concrete) went from half full to overflowing in the first 5 days of this current weather pattern and has been overflowing ever since (and even the 3/4" overflow can hardly keep up!). I almost need to put a sprinkler hose onto the overflow to spread it out a bit as it drops in one place and can start digging a hole...

A solar transfer is an idea - but if you aren't there and it keeps running past when the gravity tank is full where will that runoff go? You don't want it sliding back down the hill washed out! And a level switch or something to turn the supply solar pump off when the top tank is full is a pain in the arse to set up - not too complicated but a pain in the arse.

A 3/4" overflow is never going to keep up.
My tank's overflow is piped away from the tank and spews into a paddock.

Just had the wettest month for some time (since Oct 24 when I started keeping good records) so tank has had considerable periods of overflowing. Did consider at one stage, another tank but given we haven't needed to buy water for many years the economics didn't work out. Even with the increased cost of water we could still buy many truck loads before it equaled the overall cost of another tank.

Neerest and newest neighbour has spent just on a grand so far this season on truck loads of water. Ouch!

Sorry, getting OT from hut water.

Originally Posted by No.3

No, not hard but you have to get the right DC LED (new tech) UV filtration system to be able to work off DC off grid power. Benefit is no annual bulb changes with the LED tech, as the LEDs don't suffer the from wavelength shift like the bulbs do as they age.

Hopefully there will be a Puretec LED retrofit kit in future as annual UV bulb change isn't low dollars.

Yeah I hear that - I'm running 30w bulbs in my setup (large house spec) which is over what we need in truth but at the time there was not much in the pricing and the 30w setup came standard with the size of fittings that the rest of the system had so it was a lot less hassle installing it (plug and play basically).

I'm running the bulbs closer to 24 months than the recommended 12 months, and accepting the reduction in sterilisation effect from the aging bulb but as I said the 30w system is quite ovespec'd for our useage at this point so it's a tradeoff I am prepared to accept. The 30w setup is a lot longer than the 22w(?) setup that is the next size down, it's not about the bulb's power rating but the length of time the water travels over the UV surface. Which for us is usually much longer than it needs as our consumption is not very high... Our supply is usually very clean and I'm making sure the bird proofing is all A OK as well.

Originally Posted by zimmer

A 3/4" overflow is never going to keep up.

True, and it doesn't but the water that can't escape through the overflow goes out the hatch so no real issue.

We used to use a lot more domestic than we do, but I recently reconfigured the bore pump to be able to connect to the irrigation system and the bore pump is about 1/3rd the size of the domestic pump. Much cheaper to run ground water into the gardens with the smaller pump and also saves on running the water through the domestic filters. Also means we have a much greater effective reserve in our domestic water tank as we aren't pouring it onto the garden from the UV filter setup... Basically means we can get away with the rainwater collection for 3/4 or 4/5 of the year with only 3 or 4 top ups from the bore needed to keep us in potable water. Also means we are actually using the bore pump more often to irrigate which it likes a lot more than being left 90m down a dark wet hole and ignored!

@No.3 we've got a Puretec Hybrid G9 so a 46W UV lamp. $200 to replace and they recommend annual replacement. Would be great to get longer lasting and lower energy use LED. From what I read cleaning the quartz tube regularly is as important as lamp replacement.
Plumber specified the G9 then I independently gave Puretec the water test results and they confirmed it's appropriate. Bit of a science getting it right! Like you we can likely stretch filter and lamp replacements a bit due to volumes.

Yeah I'm yet to pull the quartz tube - I shine a torch up it and have a look each time I change the bulb but haven't yet felt I've needed to pull the quartz tube, You need a spare on hand before you touch that part, and I haven't got one as yet. I've been inspecting the 1 or 2 micron carbon block each time I've changed the filters out and it's usually very clean so not much going into the final treatment stage. I'll have to get my nerve up shortly and pull it and replace the gaskets or orings...